Access procedures in wireless communications

ABSTRACT

Wireless communications for random access procedures are described. A wireless device may send one or more messages as part of a random access procedure. The wireless may re-send a first message of the one or more messages a redundancy value equal to zero if the random access procedure is a two-step random access procedure. The wireless may re-send the first message of the one or more messages the redundancy value equal to zero if the wireless device falls back to a four-step random access procedure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims priority to U.S. patentapplication Ser. No. 16/733,316, filed Jan. 3, 2020, which claims thebenefit of U.S. Provisional Application No. 62/787,926, filed Jan. 3,2019, each of which is hereby incorporated by reference in its entirety.

BACKGROUND

Various procedures may be used to establish communication betweendevices. A wireless device may send (e.g., transmit) a message to a basestation as part of an access procedure (e.g., a random accessprocedure). The wireless device may not receive a response to themessage. The wireless device may determine to perform a new randomaccess resource selection procedure, which may lead to undesirableoutcomes, such as unsuccessful or delayed communications.

SUMMARY

The following summary presents a simplified summary of certain features.The summary is not an extensive overview and is not intended to identifykey or critical elements.

A base station may send (e.g., transmit) one or more downlink controlsignals and/or messages to a wireless device. The one or more downlinkcontrol signals and/or messages may indicate a fixed redundancy version(RV) sequence to use for re-sending (e.g., re-transmitting) one or moretransport blocks during an access procedure (e.g., a two-step randomaccess procedure). A wireless device may re-send (e.g., re-transmit) theone or more transport blocks based on the fixed RV sequence, forexample, if the random access procedure is a contention-free randomaccess procedure. The wireless device may re-send (e.g., re-transmit)the one or more transport blocks with an RV equal to zero (0), forexample, if the random access procedure is a contention-based randomaccess procedure. The wireless device may re-send (e.g., re-transmit) atransport block with the RV equal to zero (0), for example, if therandom access procedure is a two-step random access procedure or afour-step random access procedure. Using a fixed RV sequence may reducelatency and/or avoid misalignment between the wireless device and thebase station

The wireless device may perform one or more listen-before-talk (LBT)procedures on one or more uplink grants, for example, beforesending/re-sending (e.g., transmitting/re-transmitting) one or moretransport blocks in an unlicensed band. The wireless device may start(e.g., commence) a contention resolution timer, for example, based on orin response to the one-or-more LBT procedures failing. The wirelessdevice may perform a random access selection, for example, based on orin response to the one-or-more LBT procedures failing. A wireless devicemay send/re-send (e.g., transmit/re-transmit) the one or more transportblocks based on a fixed RV sequence, for example, based on the randomaccess selection. The wireless device may send/re-send (e.g.,transmit/re-transmit) the one or more transport blocks with an RV equalto zero (0). Using a fixed RV sequence and/or fallback procedures if LBTprocedures fail may reduce latency and/or avoid misalignment between thewireless device and the base station.

These and other features and advantages are described in greater detailbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

Some features are shown by way of example, and not by limitation, in theaccompanying drawings. In the drawings, like numerals reference similarelements.

FIG. 1 shows an example radio access network (RAN) architecture.

FIG. 2A shows an example user plane protocol stack.

FIG. 2B shows an example control plane protocol stack.

FIG. 3 shows an example wireless device and two base stations.

FIG. 4A, FIG. 4B, FIG. 4C, and FIG. 4D show examples of uplink anddownlink signal transmission.

FIG. 5A shows an example uplink channel mapping and example uplinkphysical signals.

FIG. 5B shows an example downlink channel mapping and example downlinkphysical signals.

FIG. 6 shows an example transmission time and/or reception time for acarrier.

FIG. 7A and FIG. 7B show example sets of orthogonal frequency divisionmultiplexing (OFDM) subcarriers.

FIG. 8 shows example OFDM radio resources.

FIG. 9A shows an example channel state information reference signal(CSI-RS) and/or synchronization signal (SS) block transmission in amulti-beam system.

FIG. 9B shows an example downlink beam management procedure.

FIG. 10 shows an example of configured bandwidth parts (BWPs).

FIG. 11A and FIG. 11B show examples of multi connectivity.

FIG. 12 shows an example of a random access procedure.

FIG. 13 shows example medium access control (MAC) entities.

FIG. 14 shows an example RAN architecture.

FIG. 15 shows example radio resource control (RRC) states.

FIG. 16 shows an example of a two-step RA procedure.

FIG. 17A, FIG. 17B, and FIG. 17C show examples of radio resourceallocations of an RA resource and one or more associated radioresources.

FIG. 18A, FIG. 18B, and FIG. 18C show examples of an RA response (RAR),a MAC subheader with backoff indicator (BI), and a MAC subheader with arandom access preamble identifier (RAPID), respectively.

FIG. 19 shows an example of contention based and contention-free randomaccess (RA) procedures with LBT.

FIG. 20 shows an example of a two-step RA procedure with LBT.

FIG. 21 shows an example of radio resource allocation for a two-step RAprocedure.

FIG. 22 shows an example of one or more LBT procedures for a two-step RAprocedure.

FIGS. 23A and 23B show examples of one or more LBT procedures for atwo-step RA procedure in an unlicensed band.

FIGS. 24A and 24B show examples of a random access response.

FIG. 25 shows an example of a random access procedure.

FIG. 26 shows an example of a random access procedure.

FIG. 27 shows an example of a random access procedure.

FIG. 28 shows an example flowchart of a random access procedure.

FIG. 29 shows an example flowchart of a random access procedure.

FIG. 30 shows an example of a random access procedure.

FIG. 31 shows an example of association/mapping in a two-step randomaccess procedure.

FIG. 32 shows an example of a random access procedure.

FIG. 33 shows an example of a random access procedure.

FIG. 34 shows example elements of a computing device that may be used toimplement any of the various devices described herein.

DETAILED DESCRIPTION

The accompanying drawings and descriptions provide examples. It is to beunderstood that the examples shown in the drawings and/or described arenon-exclusive and that there are other examples of how features shownand described may be practiced.

Examples are provided for operation of wireless communication systemswhich may be used in the technical field of multicarrier communicationsystems. More particularly, the technology described herein may relateto access procedures in communication systems.

The following acronyms are used throughout the drawings and/ordescriptions, and are provided below for convenience although otheracronyms may be introduced in the detailed description:

3GPP 3rd Generation Partnership Project 5GC 5G Core Network ACKAcknowledgement AMF Access and Mobility Management Function ARQAutomatic Repeat Request AS Access Stratum ASIC Application-SpecificIntegrated Circuit BA Bandwidth Adaptation BCCH Broadcast ControlChannel BCH Broadcast Channel BFR Beam Failure Recovery BLER Block ErrorRate BPSK Binary Phase Shift Keying BSR Buffer Status Report BWPBandwidth Part CA Carrier Aggregation CC Component Carrier CCCH CommonControl CHannel CDMA Code Division Multiple Access CN Core NetworkCORESET Control Resource Set CP Cyclic Prefix CP-OFDM CyclicPrefix-Orthogonal Frequency Division Multiplex C-RNTI Cell-Radio NetworkTemporary Identifier CS Configured Scheduling CSI Channel StateInformation CSI-RS Channel State Information-Reference Signal CQIChannel Quality Indicator CSS Common Search Space CU Central Unit DCDual Connectivity DCCH Dedicated Control Channel DCI Downlink ControlInformation DL Downlink DL-SCH Downlink Shared CHannel DM-RSDeModulation Reference Signal DRB Data Radio Bearer DRX DiscontinuousReception DTCH Dedicated Traffic Channel DU Distributed Unit EPC EvolvedPacket Core E-UTRA Evolved UMTS Terrestrial Radio Access E-UTRANEvolved-Universal Terrestrial Radio Access Network FDD FrequencyDivision Duplex FPGA Field Programmable Gate Arrays F1-C F1-Controlplane F1-U F1-User plane gNB next generation Node B HARQ HybridAutomatic Repeat reQuest HDL Hardware Description Languages IEInformation Element IP Internet Protocol LCH Logical Channel LCIDLogical Channel Identifier LTE Long Term Evolution MAC Medium AccessControl MCG Master Cell Group MCS Modulation and Coding Scheme MeNBMaster evolved Node B MIB Master Information Block MME MobilityManagement Entity MN Master Node NACK Negative Acknowledgement NASNon-Access Stratum NG CP Next Generation Control Plane NGC NextGeneration Core NG-C NG-Control plane ng-eNB next generation evolvedNode B NG-U NG-User plane NR New Radio NR MAC New Radio MAC NR PDCP NewRadio PDCP NR PHY New Radio PHYsical NR RLC New Radio RLC NR RRC NewRadio RRC NS SAI Network Slice Selection Assistance Information NULNormal Uplink O & M Operation and Maintenance OFDM Orthogonal FrequencyDivision Multiplexing PBCH Physical Broadcast CHannel PCC PrimaryComponent Carrier PCCH Paging Control CHannel PCell Primary Cell PCHPaging CHannel PDCCH Physical Downlink Control CHannel PDCP Packet DataConvergence Protocol PDSCH Physical Downlink Shared CHannel PDU ProtocolData Unit PHICH Physical HARQ Indicator CHannel PHY PHYsical PLMN PublicLand Mobile Network PMI Precoding Matrix Indicator PRACH Physical RandomAccess CHannel PRB Physical Resource Block PSCell Primary Secondary CellPSS Primary Synchronization Signal pTAG primary Timing Advance GroupPT-RS Phase Tracking Reference Signal PUCCH Physical Uplink ControlCHannel PUSCH Physical Uplink Shared CHannel QAM Quadrature AmplitudeModulation QCLed Quasi-Co-Located QCL Quasi-Co-Location QFI Quality ofService Indicator QoS Quality of Service QPSK Quadrature Phase ShiftKeying RA Random Access RACH Random Access CHannel RAN Radio AccessNetwork RAP Random Access Preamble RAT Radio Access Technology RA-RNTIRandom Access-Radio Network Temporary Identifier RB Resource Blocks RBGResource Block Groups RI Rank indicator RLC Radio Link Control RLM RadioLink Monitoring RRC Radio Resource Control RS Reference Signal RSRPReference Signal Received Power SCC Secondary Component Carrier SCellSecondary Cell SCG Secondary Cell Group SC-FDMA Single Carrier-FrequencyDivision Multiple Access SDAP Service Data Adaptation Protocol SDUService Data Unit SeNB Secondary evolved Node B SFN System Frame NumberS-GW Serving GateWay SI System Information SIB System Information BlockSINR Signal-to-Interference-plus-Noise Ratio SMF Session ManagementFunction SN Secondary Node SpCell Special Cell SR Scheduling Request SRBSignaling Radio Bearer SRS Sounding Reference Signal SS SynchronizationSignal SSB Synchronization Signal Block SSS Secondary SynchronizationSignal sTAG secondary Timing Advance Group SUL Supplementary Uplink TATiming Advance TAG Timing Advance Group TAI Tracking Area Identifier TATTime Alignment Timer TB Transport Block TC-RNTI Temporary Cell-RadioNetwork Temporary Identifier TCI Transmission Configuration IndicationTDD Time Division Duplex TDMA Time Division Multiple Access TRPTransmission and Receiving Point TTI Transmission Time Interval UCIUplink Control Information UE User Equipment UL Uplink UL-SCH UplinkShared CHannel UPF User Plane Function UPGW User Plane Gateway VHDLVHSIC Hardware Description Language Xn-C Xn-Control plane Xn-U Xn-Userplane

Examples described herein may be implemented using various physicallayer modulation and transmission mechanisms. Example transmissionmechanisms may include, but are not limited to: Code Division MultipleAccess (CDMA), Orthogonal Frequency Division Multiple Access (OFDMA),Time Division Multiple Access (TDMA), Wavelet technologies, and/or thelike. Hybrid transmission mechanisms such as TDMA/CDMA, and/or OFDM/CDMAmay be used. Various modulation schemes may be used for signaltransmission in the physical layer. Examples of modulation schemesinclude, but are not limited to: phase, amplitude, code, a combinationof these, and/or the like. An example radio transmission method mayimplement Quadrature Amplitude Modulation (QAM) using Binary Phase ShiftKeying (BPSK), Quadrature Phase Shift Keying (QPSK), 16-QAM, 64-QAM,256-QAM, 1024-QAM, and/or the like. Physical radio transmission may beenhanced by dynamically or semi-dynamically changing the modulation andcoding scheme, for example, depending on transmission requirementsand/or radio conditions.

FIG. 1 shows an example Radio Access Network (RAN) architecture. A RANnode may comprise a next generation Node B (gNB) (e.g., 120A, 120B)providing New Radio (NR) user plane and control plane protocolterminations towards a first wireless device (e.g., 110A). A RAN nodemay comprise a base station such as a next generation evolved Node B(ng-eNB) (e.g., 120C, 120D), providing Evolved UMTS Terrestrial RadioAccess (E-UTRA) user plane and control plane protocol terminationstowards a second wireless device (e.g., 110B). A first wireless device110A may communicate with a base station, such as a gNB 120A, over a Uuinterface. A second wireless device 110B may communicate with a basestation, such as an ng-eNB 120D, over a Uu interface. The wirelessdevices 110A and/or 110B may be structurally similar to wireless devicesshown in and/or described in connection with other drawing figures. TheNode B 120A, the Node B 120B, the Node B 120C, and/or the Node B 120Dmay be structurally similar to Nodes B and/or base stations shown inand/or described in connection with other drawing figures.

A base station, such as a gNB (e.g., 120A, 120B, etc.) and/or an ng-eNB(e.g., 120C, 120D, etc.) may host functions such as radio resourcemanagement and scheduling, IP header compression, encryption andintegrity protection of data, selection of Access and MobilityManagement Function (AMF) at wireless device (e.g., User Equipment (UE))attachment, routing of user plane and control plane data, connectionsetup and release, scheduling and transmission of paging messages (e.g.,originated from the AMF), scheduling and transmission of systembroadcast information (e.g., originated from the AMF or Operation andMaintenance (O&M)), measurement and measurement reporting configuration,transport level packet marking in the uplink, session management,support of network slicing, Quality of Service (QoS) flow management andmapping to data radio bearers, support of wireless devices in aninactive state (e.g., RRC INACTIVE state), distribution function forNon-Access Stratum (NAS) messages, RAN sharing, dual connectivity,and/or tight interworking between NR and E-UTRA.

One or more first base stations (e.g., gNBs 120A and 120B) and/or one ormore second base stations (e.g., ng-eNBs 120C and 120D) may beinterconnected with each other via Xn interface. A first base station(e.g., gNB 120A, 120B, etc.) or a second base station (e.g., ng-eNB120C, 120D, etc.) may be connected via NG interfaces to a network, suchas a 5G Core Network (5GC). A 5GC may comprise one or more AMF/User PlanFunction (UPF) functions (e.g., 130A and/or 130B). A base station (e.g.,a gNB and/or an ng-eNB) may be connected to a UPF via an NG-User plane(NG-U) interface. The NG-U interface may provide delivery (e.g.,non-guaranteed delivery) of user plane Protocol Data Units (PDUs)between a RAN node and the UPF. A base station (e.g., a gNB and/or anng-eNB) may be connected to an AMF via an NG-Control plane (NG-C)interface. The NG-C interface may provide, for example, functions suchas NG interface management, wireless device (e.g., UE) contextmanagement, wireless device (e.g., UE) mobility management, transport ofNAS messages, paging, PDU session management, configuration transfer,and/or warning message transmission, combinations thereof, and/or thelike.

A UPF may host functions such as anchor point for intra-/inter-RadioAccess Technology (RAT) mobility (e.g., if applicable), external PDUsession point of interconnect to data network, packet routing andforwarding, packet inspection and user plane part of policy ruleenforcement, traffic usage reporting, uplink classifier to supportrouting traffic flows to a data network, branching point to supportmulti-homed PDU session, quality of service (QoS) handling for userplane, packet filtering, gating, Uplink (UL)/Downlink (DL) rateenforcement, uplink traffic verification (e.g., Service Data Flow (SDF)to QoS flow mapping), downlink packet buffering, and/or downlink datanotification triggering.

An AMF may host functions such as NAS signaling termination, NASsignaling security, Access Stratum (AS) security control, inter CoreNetwork (CN) node signaling (e.g., for mobility between 3rd GenerationPartnership Project (3GPP) access networks), idle mode wireless devicereachability (e.g., control and execution of paging retransmission),registration area management, support of intra-system and inter-systemmobility, access authentication, access authorization including check ofroaming rights, mobility management control (e.g., subscription and/orpolicies), support of network slicing, and/or Session ManagementFunction (SMF) selection.

FIG. 2A shows an example user plane protocol stack. A Service DataAdaptation Protocol (SDAP) (e.g., 211 and 221), Packet Data ConvergenceProtocol (PDCP) (e.g., 212 and 222), Radio Link Control (RLC) (e.g., 213and 223), and Medium Access Control (MAC) (e.g., 214 and 224) sublayers,and a Physical (PHY) (e.g., 215 and 225) layer, may be terminated in awireless device (e.g., 110) and in a base station (e.g., 120) on anetwork side. A PHY layer may provide transport services to higherlayers (e.g., MAC, RRC, etc.). Services and/or functions of a MACsublayer may comprise mapping between logical channels and transportchannels, multiplexing and/or demultiplexing of MAC Service Data Units(SDUs) belonging to the same or different logical channels into and/orfrom Transport Blocks (TBs) delivered to and/or from the PHY layer,scheduling information reporting, error correction through HybridAutomatic Repeat request (HARQ) (e.g., one HARQ entity per carrier forCarrier Aggregation (CA)), priority handling between wireless devicessuch as by using dynamic scheduling, priority handling between logicalchannels of a wireless device such as by using logical channelprioritization, and/or padding. A MAC entity may support one or multiplenumerologies and/or transmission timings. Mapping restrictions in alogical channel prioritization may control which numerology and/ortransmission timing a logical channel may use. An RLC sublayer maysupport transparent mode (TM), unacknowledged mode (UM), and/oracknowledged mode (AM) transmission modes. The RLC configuration may beper logical channel with no dependency on numerologies and/orTransmission Time Interval (TTI) durations. Automatic Repeat Request(ARQ) may operate on any of the numerologies and/or TTI durations withwhich the logical channel is configured. Services and functions of thePDCP layer for the user plane may comprise, for example, sequencenumbering, header compression and decompression, transfer of user data,reordering and duplicate detection, PDCP PDU routing (e.g., such as forsplit bearers), retransmission of PDCP SDUs, ciphering, deciphering andintegrity protection, PDCP SDU discard, PDCP re-establishment and datarecovery for RLC AM, and/or duplication of PDCP PDUs. Services and/orfunctions of SDAP may comprise, for example, mapping between a QoS flowand a data radio bearer. Services and/or functions of SDAP may comprisemapping a Quality of Service Indicator (QFI) in DL and UL packets. Aprotocol entity of SDAP may be configured for an individual PDU session.

FIG. 2B shows an example control plane protocol stack. A PDCP (e.g., 233and 242), RLC (e.g., 234 and 243), and MAC (e.g., 235 and 244)sublayers, and a PHY (e.g., 236 and 245) layer, may be terminated in awireless device (e.g., 110), and in a base station (e.g., 120) on anetwork side, and perform service and/or functions described above. RRC(e.g., 232 and 241) may be terminated in a wireless device and a basestation on a network side. Services and/or functions of RRC may comprisebroadcast of system information related to AS and/or NAS; paging (e.g.,initiated by a 5GC or a RAN); establishment, maintenance, and/or releaseof an RRC connection between the wireless device and RAN; securityfunctions such as key management, establishment, configuration,maintenance, and/or release of Signaling Radio Bearers (SRBs) and DataRadio Bearers (DRBs); mobility functions; QoS management functions;wireless device measurement reporting and control of the reporting;detection of and recovery from radio link failure; and/or NAS messagetransfer to/from NAS from/to a wireless device. NAS control protocol(e.g., 231 and 251) may be terminated in the wireless device and AMF(e.g., 130) on a network side. NAS control protocol may performfunctions such as authentication, mobility management between a wirelessdevice and an AMF (e.g., for 3GPP access and non-3GPP access), and/orsession management between a wireless device and an SMF (e.g., for 3GPPaccess and non-3GPP access).

A base station may configure a plurality of logical channels for awireless device. A logical channel of the plurality of logical channelsmay correspond to a radio bearer. The radio bearer may be associatedwith a QoS requirement. A base station may configure a logical channelto be mapped to one or more TTIs and/or numerologies in a plurality ofTTIs and/or numerologies. The wireless device may receive DownlinkControl Information (DCI) via a Physical Downlink Control CHannel(PDCCH) indicating an uplink grant. The uplink grant may be for a firstTTI and/or a first numerology and may indicate uplink resources fortransmission of a TB. The base station may configure each logicalchannel in the plurality of logical channels with one or more parametersto be used by a logical channel prioritization procedure at the MAClayer of the wireless device. The one or more parameters may comprise,for example, priority, prioritized bit rate, etc. A logical channel inthe plurality of logical channels may correspond to one or more bufferscomprising data associated with the logical channel. The logical channelprioritization procedure may allocate the uplink resources to one ormore first logical channels in the plurality of logical channels and/orto one or more MAC Control Elements (CEs). The one or more first logicalchannels may be mapped to the first TTI and/or the first numerology. TheMAC layer at the wireless device may multiplex one or more MAC CEsand/or one or more MAC SDUs (e.g., logical channel) in a MAC PDU (e.g.,TB). The MAC PDU may comprise a MAC header comprising a plurality of MACsub-headers. A MAC sub-header in the plurality of MAC sub-headers maycorrespond to a MAC CE or a MAC SUD (e.g., logical channel) in the oneor more MAC CEs and/or in the one or more MAC SDUs. A MAC CE and/or alogical channel may be configured with a Logical Channel IDentifier(LCD). An LCID for a logical channel and/or a MAC CE may be fixed and/orpre-configured. An LCID for a logical channel and/or MAC CE may beconfigured for the wireless device by the base station. The MACsub-header corresponding to a MAC CE and/or a MAC SDU may comprise anLCID associated with the MAC CE and/or the MAC SDU.

A base station may activate, deactivate, and/or impact one or moreprocesses (e.g., set values of one or more parameters of the one or moreprocesses or start and/or stop one or more timers of the one or moreprocesses) at the wireless device, for example, by using one or more MACcommands. The one or more MAC commands may comprise one or more MACcontrol elements. The one or more processes may comprise activationand/or deactivation of PDCP packet duplication for one or more radiobearers. The base station may send (e.g., transmit) a MAC CE comprisingone or more fields. The values of the fields may indicate activationand/or deactivation of PDCP duplication for the one or more radiobearers. The one or more processes may comprise Channel StateInformation (CSI) transmission of on one or more cells. The base stationmay send (e.g., transmit) one or more MAC CEs indicating activationand/or deactivation of the CSI transmission on the one or more cells.The one or more processes may comprise activation and/or deactivation ofone or more secondary cells. The base station may send (e.g., transmit)a MAC CE indicating activation and/or deactivation of one or moresecondary cells. The base station may send (e.g., transmit) one or moreMAC CEs indicating starting and/or stopping of one or more DiscontinuousReception (DRX) timers at the wireless device. The base station may send(e.g., transmit) one or more MAC CEs that indicate one or more timingadvance values for one or more Timing Advance Groups (TAGs).

FIG. 3 shows an example of base stations (base station 1, 120A, and basestation 2, 120B) and a wireless device 110. The wireless device 110 maycomprise a UE or any other wireless device. The base station (e.g.,120A, 120B) may comprise a Node B, eNB, gNB, ng-eNB, or any other basestation. A wireless device and/or a base station may perform one or morefunctions of a relay node. The base station 1, 120A, may comprise atleast one communication interface 320A (e.g., a wireless modem, anantenna, a wired modem, and/or the like), at least one processor 321A,and at least one set of program code instructions 323A that may bestored in non-transitory memory 322A and executable by the at least oneprocessor 321A. The base station 2, 120B, may comprise at least onecommunication interface 320B, at least one processor 321B, and at leastone set of program code instructions 323B that may be stored innon-transitory memory 322B and executable by the at least one processor321B.

A base station may comprise any number of sectors, for example: 1, 2, 3,4, or 6 sectors. A base station may comprise any number of cells, forexample, ranging from 1 to 50 cells or more. A cell may be categorized,for example, as a primary cell or secondary cell. At Radio ResourceControl (RRC) connection establishment, re-establishment, handover,etc., a serving cell may provide NAS (non-access stratum) mobilityinformation (e.g., Tracking Area Identifier (TAI)). At RRC connectionre-establishment and/or handover, a serving cell may provide securityinput. This serving cell may be referred to as the Primary Cell (PCell).In the downlink, a carrier corresponding to the PCell may be a DLPrimary Component Carrier (PCC). In the uplink, a carrier may be an ULPCC. Secondary Cells (SCells) may be configured to form together with aPCell a set of serving cells, for example, depending on wireless devicecapabilities. In a downlink, a carrier corresponding to an SCell may bea downlink secondary component carrier (DL SCC). In an uplink, a carriermay be an uplink secondary component carrier (UL SCC). An SCell may ormay not have an uplink carrier.

A cell, comprising a downlink carrier and optionally an uplink carrier,may be assigned a physical cell ID and/or a cell index. A carrier(downlink and/or uplink) may belong to one cell. The cell ID and/or cellindex may identify the downlink carrier and/or uplink carrier of thecell (e.g., depending on the context it is used). A cell ID may beequally referred to as a carrier ID, and a cell index may be referred toas a carrier index. A physical cell ID and/or a cell index may beassigned to a cell. A cell ID may be determined using a synchronizationsignal transmitted via a downlink carrier. A cell index may bedetermined using RRC messages. A first physical cell ID for a firstdownlink carrier may indicate that the first physical cell ID is for acell comprising the first downlink carrier. The same concept may beused, for example, with carrier activation and/or deactivation (e.g.,secondary cell activation and/or deactivation). A first carrier that isactivated may indicate that a cell comprising the first carrier isactivated.

A base station may send (e.g., transmit) to a wireless device one ormore messages (e.g., RRC messages) comprising a plurality ofconfiguration parameters for one or more cells. One or more cells maycomprise at least one primary cell and at least one secondary cell. AnRRC message may be broadcasted and/or unicasted to the wireless device.Configuration parameters may comprise common parameters and dedicatedparameters.

Services and/or functions of an RRC sublayer may comprise at least oneof: broadcast of system information related to AS and/or NAS; paginginitiated by a 5GC and/or an NG-RAN; establishment, maintenance, and/orrelease of an RRC connection between a wireless device and an NG-RAN,which may comprise at least one of addition, modification, and/orrelease of carrier aggregation; and/or addition, modification, and/orrelease of dual connectivity in NR or between E-UTRA and NR. Servicesand/or functions of an RRC sublayer may comprise at least one ofsecurity functions comprising key management; establishment,configuration, maintenance, and/or release of Signaling Radio Bearers(SRBs) and/or Data Radio Bearers (DRBs); mobility functions which maycomprise at least one of a handover (e.g., intra NR mobility orinter-RAT mobility) and/or a context transfer; and/or a wireless devicecell selection and/or reselection and/or control of cell selection andreselection. Services and/or functions of an RRC sublayer may compriseat least one of QoS management functions; a wireless device measurementconfiguration/reporting; detection of and/or recovery from radio linkfailure; and/or NAS message transfer to and/or from a core networkentity (e.g., AMF, Mobility Management Entity (MME)) from and/or to thewireless device.

An RRC sublayer may support an RRC_Idle state, an RRC_Inactive state,and/or an RRC_Connected state for a wireless device. In an RRC_Idlestate, a wireless device may perform at least one of: Public Land MobileNetwork (PLMN) selection; receiving broadcasted system information; cellselection and/or re-selection; monitoring and/or receiving a paging formobile terminated data initiated by 5GC; paging for mobile terminateddata area managed by 5GC; and/or DRX for CN paging configured via NAS.In an RRC_Inactive state, a wireless device may perform at least one of:receiving broadcasted system information; cell selection and/orre-selection; monitoring and/or receiving a RAN and/or CN paginginitiated by an NG-RAN and/or a 5GC; RAN-based notification area (RNA)managed by an NG-RAN; and/or DRX for a RAN and/or CN paging configuredby NG-RAN/NAS. In an RRC Idle state of a wireless device, a base station(e.g., NG-RAN) may keep a 5GC-NG-RAN connection (e.g., both C/U-planes)for the wireless device; and/or store a wireless device AS context forthe wireless device. In an RRC Connected state of a wireless device, abase station (e.g., NG-RAN) may perform at least one of: establishmentof 5GC-NG-RAN connection (both C/U-planes) for the wireless device;storing a UE AS context for the wireless device; send (e.g., transmit)and/or receive of unicast data to and/or from the wireless device;and/or network-controlled mobility based on measurement results receivedfrom the wireless device. In an RRC Connected state of a wirelessdevice, an NG-RAN may know a cell to which the wireless device belongs.

System information (SI) may be divided into minimum SI and other SI. Theminimum SI may be periodically broadcast. The minimum SI may comprisebasic information required for initial access and/or information foracquiring any other SI broadcast periodically and/or provisionedon-demand (e.g., scheduling information). The other SI may either bebroadcast, and/or be provisioned in a dedicated manner, such as eithertriggered by a network and/or upon request from a wireless device. Aminimum SI may be transmitted via two different downlink channels usingdifferent messages (e.g., MasterinformationBlock andSystemInformationBlockType1). Another SI may be transmitted viaSystemInformationBlockType2. For a wireless device in an RRC_Connectedstate, dedicated RRC signaling may be used for the request and deliveryof the other SI. For the wireless device in the RRC_Idle state and/or inthe RRC_Inactive state, the request may trigger a RA procedure.

A wireless device may report its radio access capability information,which may be static. A base station may request one or more indicationsof capabilities for a wireless device to report based on bandinformation. A temporary capability restriction request may be sent bythe wireless device (e.g., if allowed by a network) to signal thelimited availability of some capabilities (e.g., due to hardwaresharing, interference, and/or overheating) to the base station. The basestation may confirm or reject the request. The temporary capabilityrestriction may be transparent to 5GC (e.g., static capabilities may bestored in 5GC).

A wireless device may have an RRC connection with a network, forexample, if CA is configured. At RRC connection establishment,re-establishment, and/or handover procedures, a serving cell may provideNAS mobility information. At RRC connection re-establishment and/orhandover, a serving cell may provide a security input. This serving cellmay be referred to as the PCell. SCells may be configured to formtogether with the PCell a set of serving cells, for example, dependingon the capabilities of the wireless device. The configured set ofserving cells for the wireless device may comprise a PCell and one ormore SCells.

The reconfiguration, addition, and/or removal of SCells may be performedby RRC messaging. At intra-NR handover, RRC may add, remove, and/orreconfigure SCells for usage with the target PCell. Dedicated RRCsignaling may be used (e.g., if adding a new SCell) to send all requiredsystem information of the SCell (e.g., if in connected mode, wirelessdevices may not acquire broadcasted system information directly from theSCells).

The purpose of an RRC connection reconfiguration procedure may be tomodify an RRC connection, (e.g., to establish, modify, and/or releaseRBs; to perform handover; to setup, modify, and/or release measurements,for example, to add, modify, and/or release SCells and cell groups). NASdedicated information may be transferred from the network to thewireless device, for example, as part of the RRC connectionreconfiguration procedure. The RRCConnectionReconfiguration message maybe a command to modify an RRC connection. One or more RRC messages mayconvey information for measurement configuration, mobility control,and/or radio resource configuration (e.g., RBs, MAC main configuration,and/or physical channel configuration), which may comprise anyassociated dedicated NAS information and/or security configuration. Thewireless device may perform an SCell release, for example, if thereceived RRC Connection Reconfiguration message includes thesCellToReleaseList. The wireless device may perform SCell additions ormodification, for example, if the received RRC ConnectionReconfiguration message includes the sCellToAddModList.

An RRC connection establishment, reestablishment, and/or resumeprocedure may be to establish, reestablish, and/or resume an RRCconnection, respectively. An RRC connection establishment procedure maycomprise SRB1 establishment. The RRC connection establishment proceduremay be used to transfer the initial NAS dedicated information and/ormessage from a wireless device to an E-UTRAN. TheRRCConnectionReestablishment message may be used to re-establish SRB1.

A measurement report procedure may be used to transfer measurementresults from a wireless device to an NG-RAN. The wireless device mayinitiate a measurement report procedure, for example, after successfulsecurity activation. A measurement report message may be used to send(e.g., transmit) measurement results.

The wireless device 110 may comprise at least one communicationinterface 310 (e.g., a wireless modem, an antenna, and/or the like), atleast one processor 314, and at least one set of program codeinstructions 316 that may be stored in non-transitory memory 315 andexecutable by the at least one processor 314. The wireless device 110may further comprise at least one of at least one speaker and/ormicrophone 311, at least one keypad 312, at least one display and/ortouchpad 313, at least one power source 317, at least one globalpositioning system (GPS) chipset 318, and/or other peripherals 319.

The processor 314 of the wireless device 110, the processor 321A of thebase station 1 120A, and/or the processor 321B of the base station 2120B may comprise at least one of a general-purpose processor, a digitalsignal processor (DSP), a controller, a microcontroller, an applicationspecific integrated circuit (ASIC), a field programmable gate array(FPGA) and/or other programmable logic device, discrete gate and/ortransistor logic, discrete hardware components, and/or the like. Theprocessor 314 of the wireless device 110, the processor 321A in basestation 1 120A, and/or the processor 321B in base station 2 120B mayperform at least one of signal coding and/or processing, dataprocessing, power control, input/output processing, and/or any otherfunctionality that may enable the wireless device 110, the base station1 120A and/or the base station 2 120B to operate in a wirelessenvironment.

The processor 314 of the wireless device 110 may be connected to and/orin communication with the speaker and/or microphone 311, the keypad 312,and/or the display and/or touchpad 313. The processor 314 may receiveuser input data from and/or provide user output data to the speakerand/or microphone 311, the keypad 312, and/or the display and/ortouchpad 313. The processor 314 in the wireless device 110 may receivepower from the power source 317 and/or may be configured to distributethe power to the other components in the wireless device 110. The powersource 317 may comprise at least one of one or more dry cell batteries,solar cells, fuel cells, and/or the like. The processor 314 may beconnected to the GPS chipset 318. The GPS chipset 318 may be configuredto provide geographic location information of the wireless device 110.

The processor 314 of the wireless device 110 may further be connected toand/or in communication with other peripherals 319, which may compriseone or more software and/or hardware modules that may provide additionalfeatures and/or functionalities. For example, the peripherals 319 maycomprise at least one of an accelerometer, a satellite transceiver, adigital camera, a universal serial bus (USB) port, a hands-free headset,a frequency modulated (FM) radio unit, a media player, an Internetbrowser, and/or the like.

The communication interface 320A of the base station 1, 120A, and/or thecommunication interface 320B of the base station 2, 120B, may beconfigured to communicate with the communication interface 310 of thewireless device 110, for example, via a wireless link 330A and/or via awireless link 330B, respectively. The communication interface 320A ofthe base station 1, 120A, may communicate with the communicationinterface 320B of the base station 2 and/or other RAN and/or corenetwork nodes.

The wireless link 330A and/or the wireless link 330B may comprise atleast one of a bi-directional link and/or a directional link. Thecommunication interface 310 of the wireless device 110 may be configuredto communicate with the communication interface 320A of the base station1 120A and/or with the communication interface 320B of the base station2 120B. The base station 1 120A and the wireless device 110, and/or thebase station 2 120B and the wireless device 110, may be configured tosend and receive TBs, for example, via the wireless link 330A and/or viathe wireless link 330B, respectively. The wireless link 330A and/or thewireless link 330B may use at least one frequency carrier.Transceiver(s) may be used. A transceiver may be a device that comprisesboth a transmitter and a receiver. Transceivers may be used in devicessuch as wireless devices, base stations, relay nodes, computing devices,and/or the like. Radio technology may be implemented in thecommunication interface 310, 320A, and/or 320B, and the wireless link330A and/or 330B. The radio technology may comprise one or more elementsshown in FIG. 4A, FIG. 4B, FIG. 4C, FIG. 4D, FIG. 6 , FIG. 7A, FIG. 7B,FIG. 8 , and associated text, described below.

Other nodes in a wireless network (e.g., AMF, UPF, SMF, etc.) maycomprise one or more communication interfaces, one or more processors,and memory storing instructions. A node (e.g., wireless device, basestation, AMF, SMF, UPF, servers, switches, antennas, and/or the like)may comprise one or more processors, and memory storing instructionsthat when executed by the one or more processors causes the node toperform certain processes and/or functions. Single-carrier and/ormulti-carrier communication operation may be performed. A non-transitorytangible computer readable media may comprise instructions executable byone or more processors to cause operation of single-carrier and/ormulti-carrier communications. An article of manufacture may comprise anon-transitory tangible computer readable machine-accessible mediumhaving instructions encoded thereon for enabling programmable hardwareto cause a node to enable operation of single-carrier and/ormulti-carrier communications. The node may include processors, memory,interfaces, and/or the like.

An interface may comprise at least one of a hardware interface, afirmware interface, a software interface, and/or a combination thereof.The hardware interface may comprise connectors, wires, and/or electronicdevices such as drivers, amplifiers, and/or the like. The softwareinterface may comprise code stored in a memory device to implementprotocol(s), protocol layers, communication drivers, device drivers,combinations thereof, and/or the like. The firmware interface maycomprise a combination of embedded hardware and/or code stored in(and/or in communication with) a memory device to implement connections,electronic device operations, protocol(s), protocol layers,communication drivers, device drivers, hardware operations, combinationsthereof, and/or the like.

A communication network may comprise the wireless device 110, the basestation 1, 120A, the base station 2, 120B, and/or any other device. Thecommunication network may comprise any number and/or type of devices,such as, for example, computing devices, wireless devices, mobiledevices, handsets, tablets, laptops, internet of things (IoT) devices,hotspots, cellular repeaters, computing devices, and/or, more generally,user equipment (e.g., UE). Although one or more of the above types ofdevices may be referenced herein (e.g., UE, wireless device, computingdevice, etc.), it should be understood that any device herein maycomprise any one or more of the above types of devices or similardevices. The communication network, and any other network referencedherein, may comprise an LTE network, a 5G network, or any other networkfor wireless communications. Apparatuses, systems, and/or methodsdescribed herein may generally be described as implemented on one ormore devices (e.g., wireless device, base station, eNB, gNB, computingdevice, etc.), in one or more networks, but it will be understood thatone or more features and steps may be implemented on any device and/orin any network. As used throughout, the term “base station” may compriseone or more of: a base station, a node, a Node B, a gNB, an eNB, anng-eNB, a relay node (e.g., an integrated access and backhaul (IAB)node), a donor node (e.g., a donor eNB, a donor gNB, etc.), an accesspoint (e.g., a WiFi access point), a computing device, a device capableof wirelessly communicating, or any other device capable of sendingand/or receiving signals. As used throughout, the term “wireless device”may comprise one or more of: a UE, a handset, a mobile device, acomputing device, a node, a device capable of wirelessly communicating,or any other device capable of sending and/or receiving signals. Anyreference to one or more of these terms/devices also considers use ofany other term/device mentioned above.

FIG. 4A, FIG. 4B, FIG. 4C and FIG. 4D show examples of uplink anddownlink signal transmission. FIG. 4A shows an example uplinktransmitter for at least one physical channel. A baseband signalrepresenting a physical uplink shared channel may perform one or morefunctions. The one or more functions may comprise at least one of:scrambling (e.g., by Scrambling); modulation of scrambled bits togenerate complex-valued symbols (e.g., by a Modulation mapper); mappingof the complex-valued modulation symbols onto one or severaltransmission layers (e.g., by a Layer mapper); transform precoding togenerate complex-valued symbols (e.g., by a Transform precoder);precoding of the complex-valued symbols (e.g., by a Precoder); mappingof precoded complex-valued symbols to resource elements (e.g., by aResource element mapper); generation of complex-valued time-domainSingle Carrier-Frequency Division Multiple Access (SC-FDMA) or CP-OFDMsignal for an antenna port (e.g., by a signal gen.); and/or the like. ASC-FDMA signal for uplink transmission may be generated, for example, iftransform precoding is enabled. A CP-OFDM signal for uplink transmissionmay be generated by FIG. 4A, for example, if transform precoding is notenabled. These functions are shown as examples and other mechanisms maybe implemented.

FIG. 4B shows an example of modulation and up-conversion to the carrierfrequency of a complex-valued SC-FDMA or CP-OFDM baseband signal for anantenna port and/or for the complex-valued Physical Random AccessCHannel (PRACH) baseband signal. Filtering may be performed prior totransmission.

FIG. 4C shows an example of downlink transmissions. The baseband signalrepresenting a downlink physical channel may perform one or morefunctions. The one or more functions may comprise: scrambling of codedbits in a codeword to be transmitted on a physical channel (e.g., byScrambling); modulation of scrambled bits to generate complex-valuedmodulation symbols (e.g., by a Modulation mapper); mapping of thecomplex-valued modulation symbols onto one or several transmissionlayers (e.g., by a Layer mapper); precoding of the complex-valuedmodulation symbols on a layer for transmission on the antenna ports(e.g., by Precoding); mapping of complex-valued modulation symbols foran antenna port to resource elements (e.g., by a Resource elementmapper); generation of complex-valued time-domain OFDM signal for anantenna port (e.g., by an OFDM signal gen.); and/or the like. Thesefunctions are shown as examples and other mechanisms may be implemented.

A base station may send (e.g., transmit) a first symbol and a secondsymbol on an antenna port, to a wireless device. The wireless device mayinfer the channel (e.g., fading gain, multipath delay, etc.) forconveying the second symbol on the antenna port, from the channel forconveying the first symbol on the antenna port. A first antenna port anda second antenna port may be quasi co-located, for example, if one ormore large-scale properties of the channel over which a first symbol onthe first antenna port is conveyed may be inferred from the channel overwhich a second symbol on a second antenna port is conveyed. The one ormore large-scale properties may comprise at least one of: delay spread;Doppler spread; Doppler shift; average gain; average delay; and/orspatial receiving (Rx) parameters.

FIG. 4D shows an example modulation and up-conversion to the carrierfrequency of the complex-valued OFDM baseband signal for an antennaport. Filtering may be performed prior to transmission.

FIG. 5A shows example uplink channel mapping and example uplink physicalsignals. A physical layer may provide one or more information transferservices to a MAC and/or one or more higher layers. The physical layermay provide the one or more information transfer services to the MAC viaone or more transport channels. An information transfer service mayindicate how and/or with what characteristics data is transferred overthe radio interface.

Uplink transport channels may comprise an Uplink-Shared CHannel (UL-SCH)501 and/or a Random Access CHannel (RACH) 502. A wireless device maysend (e.g., transmit) one or more uplink DM-RSs 506 to a base stationfor channel estimation, for example, for coherent demodulation of one ormore uplink physical channels (e.g., PUSCH 503 and/or PUCCH 504). Thewireless device may send (e.g., transmit) to a base station at least oneuplink DM-RS 506 with PUSCH 503 and/or PUCCH 504, wherein the at leastone uplink DM-RS 506 may be spanning a same frequency range as acorresponding physical channel. The base station may configure thewireless device with one or more uplink DM-RS configurations. At leastone DM-RS configuration may support a front-loaded DM-RS pattern. Afront-loaded DM-RS may be mapped over one or more OFDM symbols (e.g., 1or 2 adjacent OFDM symbols). One or more additional uplink DM-RS may beconfigured to send (e.g., transmit) at one or more symbols of a PUSCHand/or PUCCH. The base station may semi-statically configure thewireless device with a maximum number of front-loaded DM-RS symbols forPUSCH and/or PUCCH. The wireless device may schedule a single-symbolDM-RS and/or double symbol DM-RS based on a maximum number offront-loaded DM-RS symbols, wherein the base station may configure thewireless device with one or more additional uplink DM-RS for PUSCHand/or PUCCH. A new radio network may support, for example, at least forCP-OFDM, a common DM-RS structure for DL and UL, wherein a DM-RSlocation, DM-RS pattern, and/or scrambling sequence may be same ordifferent.

Whether or not an uplink PT-RS 507 is present may depend on an RRCconfiguration. A presence of the uplink PT-RS may be wirelessdevice-specifically configured. A presence and/or a pattern of theuplink PT-RS 507 in a scheduled resource may be wirelessdevice-specifically configured by a combination of RRC signaling and/orassociation with one or more parameters used for other purposes (e.g.,Modulation and Coding Scheme (MCS)) which may be indicated by DCI. Ifconfigured, a dynamic presence of uplink PT-RS 507 may be associatedwith one or more DCI parameters comprising at least a MCS. A radionetwork may support a plurality of uplink PT-RS densities defined intime/frequency domain. If present, a frequency domain density may beassociated with at least one configuration of a scheduled bandwidth. Awireless device may assume a same precoding for a DMRS port and a PT-RSport. A number of PT-RS ports may be less than a number of DM-RS portsin a scheduled resource. The uplink PT-RS 507 may be confined in thescheduled time/frequency duration for a wireless device.

A wireless device may send (e.g., transmit) an SRS 508 to a base stationfor channel state estimation, for example, to support uplink channeldependent scheduling and/or link adaptation. The SRS 508 sent (e.g.,transmitted) by the wireless device may allow for the base station toestimate an uplink channel state at one or more different frequencies. Abase station scheduler may use an uplink channel state to assign one ormore resource blocks of a certain quality (e.g., above a qualitythreshold) for an uplink PUSCH transmission from the wireless device.The base station may semi-statically configure the wireless device withone or more SRS resource sets. For an SRS resource set, the base stationmay configure the wireless device with one or more SRS resources. An SRSresource set applicability may be configured by a higher layer (e.g.,RRC) parameter. An SRS resource in each of one or more SRS resource setsmay be sent (e.g., transmitted) at a time instant, for example, if ahigher layer parameter indicates beam management. The wireless devicemay send (e.g., transmit) one or more SRS resources in different SRSresource sets simultaneously. A new radio network may support aperiodic,periodic, and/or semi-persistent SRS transmissions. The wireless devicemay send (e.g., transmit) SRS resources, for example, based on one ormore trigger types. The one or more trigger types may comprise higherlayer signaling (e.g., RRC) and/or one or more DCI formats (e.g., atleast one DCI format may be used for a wireless device to select atleast one of one or more configured SRS resource sets). An SRS triggertype 0 may refer to an SRS triggered based on a higher layer signaling.An SRS trigger type 1 may refer to an SRS triggered based on one or moreDCI formats. The wireless device may be configured to send (e.g.,transmit) the SRS 508 after a transmission of PUSCH 503 andcorresponding uplink DM-RS 506, for example, if PUSCH 503 and the SRS508 are transmitted in a same slot.

A base station may semi-statically configure a wireless device with oneor more SRS configuration parameters indicating at least one offollowing: an SRS resource configuration identifier, a number of SRSports, time domain behavior of SRS resource configuration (e.g., anindication of periodic, semi-persistent, or aperiodic SRS), slot(mini-slot, and/or subframe) level periodicity and/or offset for aperiodic and/or aperiodic SRS resource, a number of OFDM symbols in aSRS resource, starting OFDM symbol of a SRS resource, an SRS bandwidth,a frequency hopping bandwidth, a cyclic shift, and/or an SRS sequenceID.

FIG. 5B shows an example downlink channel mapping and downlink physicalsignals. Downlink transport channels may comprise a Downlink-SharedCHannel (DL-SCH) 511, a Paging CHannel (PCH) 512, and/or a BroadcastCHannel (BCH) 513. A transport channel may be mapped to one or morecorresponding physical channels. A UL-SCH 501 may be mapped to aPhysical Uplink Shared CHannel (PUSCH) 503. A RACH 502 may be mapped toa PRACH 505. A DL-SCH 511 and a PCH 512 may be mapped to a PhysicalDownlink Shared CHannel (PDSCH) 514. A BCH 513 may be mapped to aPhysical Broadcast CHannel (PBCH) 516.

A radio network may comprise one or more downlink and/or uplinktransport channels. The radio network may comprise one or more physicalchannels without a corresponding transport channel. The one or morephysical channels may be used for an Uplink Control Information (UCI)509 and/or a Downlink Control Information (DCI) 517. A Physical UplinkControl CHannel (PUCCH) 504 may carry UCI 509 from a wireless device toa base station. A Physical Downlink Control CHannel (PDCCH) 515 maycarry the DCI 517 from a base station to a wireless device. The radionetwork (e.g., NR) may support the UCI 509 multiplexing in the PUSCH503, for example, if the UCI 509 and the PUSCH 503 transmissions maycoincide in a slot (e.g., at least in part). The UCI 509 may comprise atleast one of a CSI, an Acknowledgement (ACK)/Negative Acknowledgement(NACK), and/or a scheduling request. The DCI 517 via the PDCCH 515 mayindicate at least one of following: one or more downlink assignmentsand/or one or more uplink scheduling grants.

In uplink, a wireless device may send (e.g., transmit) one or moreReference Signals (RSs) to a base station. The one or more RSs maycomprise at least one of a Demodulation-RS (DM-RS) 506, a PhaseTracking-RS (PT-RS) 507, and/or a Sounding RS (SRS) 508. In downlink, abase station may send (e.g., transmit, unicast, multicast, and/orbroadcast) one or more RSs to a wireless device. The one or more RSs maycomprise at least one of a Primary Synchronization Signal(PSS)/Secondary Synchronization Signal (SSS) 521, a CSI-RS 522, a DM-RS523, and/or a PT-RS 524.

In a time domain, an SS/PBCH block may comprise one or more OFDM symbols(e.g., 4 OFDM symbols numbered in increasing order from 0 to 3) withinthe SS/PBCH block. An SS/PBCH block may comprise the PSS/SSS 521 and/orthe PBCH 516. In the frequency domain, an SS/PBCH block may comprise oneor more contiguous subcarriers (e.g., 240 contiguous subcarriers withthe subcarriers numbered in increasing order from 0 to 239) within theSS/PBCH block. The PSS/SSS 521 may occupy, for example, 1 OFDM symboland 127 subcarriers. The PBCH 516 may span across, for example, 3 OFDMsymbols and 240 subcarriers. A wireless device may assume that one ormore SS/PBCH blocks transmitted with a same block index may be quasico-located, for example, with respect to Doppler spread, Doppler shift,average gain, average delay, and/or spatial Rx parameters. A wirelessdevice may not assume quasi co-location for other SS/PBCH blocktransmissions. A periodicity of an SS/PBCH block may be configured by aradio network (e.g., by an RRC signaling). One or more time locations inwhich the SS/PBCH block may be sent may be determined by sub-carrierspacing. A wireless device may assume a band-specific sub-carrierspacing for an SS/PBCH block, for example, unless a radio network hasconfigured the wireless device to assume a different sub-carrierspacing.

The downlink CSI-RS 522 may be used for a wireless device to acquirechannel state information. A radio network may support periodic,aperiodic, and/or semi-persistent transmission of the downlink CSI-RS522. A base station may semi-statically configure and/or reconfigure awireless device with periodic transmission of the downlink CSI-RS 522. Aconfigured CSI-RS resources may be activated and/or deactivated. Forsemi-persistent transmission, an activation and/or deactivation of aCSI-RS resource may be triggered dynamically. A CSI-RS configuration maycomprise one or more parameters indicating at least a number of antennaports. A base station may configure a wireless device with 32 ports, orany other number of ports. A base station may semi-statically configurea wireless device with one or more CSI-RS resource sets. One or moreCSI-RS resources may be allocated from one or more CSI-RS resource setsto one or more wireless devices. A base station may semi-staticallyconfigure one or more parameters indicating CSI RS resource mapping, forexample, time-domain location of one or more CSI-RS resources, abandwidth of a CSI-RS resource, and/or a periodicity. A wireless devicemay be configured to use the same OFDM symbols for the downlink CSI-RS522 and the Control Resource Set (CORESET), for example, if the downlinkCSI-RS 522 and the CORESET are spatially quasi co-located and resourceelements associated with the downlink CSI-RS 522 are the outside of PRBsconfigured for the CORESET. A wireless device may be configured to usethe same OFDM symbols for downlink CSI-RS 522 and SSB/PBCH, for example,if the downlink CSI-RS 522 and SSB/PBCH are spatially quasi co-locatedand resource elements associated with the downlink CSI-RS 522 areoutside of the PRBs configured for the S SB/PB CH.

A wireless device may send (e.g., transmit) one or more downlink DM-RSs523 to a base station for channel estimation, for example, for coherentdemodulation of one or more downlink physical channels (e.g., PDSCH514). A radio network may support one or more variable and/orconfigurable DM-RS patterns for data demodulation. At least one downlinkDM-RS configuration may support a front-loaded DM-RS pattern. Afront-loaded DM-RS may be mapped over one or more OFDM symbols (e.g., 1or 2 adjacent OFDM symbols). A base station may semi-staticallyconfigure a wireless device with a maximum number of front-loaded DM-RSsymbols for PDSCH 514. A DM-RS configuration may support one or moreDM-RS ports. A DM-RS configuration may support at least 8 orthogonaldownlink DM-RS ports, for example, for single user-MIMO. ADM-RSconfiguration may support 12 orthogonal downlink DM-RS ports, forexample, for multiuser-MIMO. A radio network may support, for example,at least for CP-OFDM, a common DM-RS structure for DL and UL, wherein aDM-RS location, DM-RS pattern, and/or scrambling sequence may be thesame or different.

Whether or not the downlink PT-RS 524 is present may depend on an RRCconfiguration. A presence of the downlink PT-RS 524 may be wirelessdevice-specifically configured. A presence and/or a pattern of thedownlink PT-RS 524 in a scheduled resource may be wirelessdevice-specifically configured, for example, by a combination of RRCsignaling and/or an association with one or more parameters used forother purposes (e.g., MCS) which may be indicated by the DCI. Ifconfigured, a dynamic presence of the downlink PT-RS 524 may beassociated with one or more DCI parameters comprising at least MCS. Aradio network may support a plurality of PT-RS densities in atime/frequency domain. If present, a frequency domain density may beassociated with at least one configuration of a scheduled bandwidth. Awireless device may assume the same precoding for a DMRS port and aPT-RS port. A number of PT-RS ports may be less than a number of DM-RSports in a scheduled resource. The downlink PT-RS 524 may be confined inthe scheduled time/frequency duration for a wireless device.

FIG. 6 shows an example transmission and/or reception time of a carrier,as well as an example frame structure, for a carrier. A multicarrierOFDM communication system may include one or more carriers, for example,ranging from 1 to 32 carriers (such as for carrier aggregation) orranging from 1 to 64 carriers (such as for dual connectivity). Differentradio frame structures may be supported (e.g., for FDD and/or for TDDduplex mechanisms). FIG. 6 shows an example frame structure. Downlinkand uplink transmissions may be organized into radio frames 601. Radioframe duration may be 10 milliseconds (ms). A 10 ms radio frame 601 maybe divided into ten equally sized subframes 602, each with a 1 msduration. Subframe(s) may comprise one or more slots (e.g., slots 603and 605) depending on subcarrier spacing and/or CP length. For example,a subframe with 15 kHz, 30 kHz, 60 kHz, 120 kHz, 240 kHz and 480 kHzsubcarrier spacing may comprise one, two, four, eight, sixteen andthirty-two slots, respectively. In FIG. 6 , a subframe may be dividedinto two equally sized slots 603 with 0.5 ms duration. For example, 10subframes may be available for downlink transmission and 10 subframesmay be available for uplink transmissions in a 10 ms interval. Othersubframe durations such as, for example, 0.5 ms, 1 ms, 2 ms, and 5 msmay be supported. Uplink and downlink transmissions may be separated inthe frequency domain. Slot(s) may include a plurality of OFDM symbols604. The number of OFDM symbols 604 in a slot 605 may depend on thecyclic prefix length. A slot may be 14 OFDM symbols for the samesubcarrier spacing of up to 480 kHz with normal CP. A slot may be 12OFDM symbols for the same subcarrier spacing of 60 kHz with extended CP.A slot may comprise downlink, uplink, and/or a downlink part and anuplink part, and/or alike.

FIG. 7A shows example sets of OFDM subcarriers. A base station maycommunicate with a wireless device using a carrier having an examplechannel bandwidth 700. Arrow(s) may depict a subcarrier in amulticarrier OFDM system. The OFDM system may use technology such asOFDM technology, SC-FDMA technology, and/or the like. An arrow 701 showsa subcarrier transmitting information symbols. A subcarrier spacing 702,between two contiguous subcarriers in a carrier, may be any one of 15kHz, 30 kHz, 60 kHz, 120 kHz, 240 kHz, or any other frequency. Differentsubcarrier spacing may correspond to different transmissionnumerologies. A transmission numerology may comprise at least: anumerology index; a value of subcarrier spacing; and/or a type of cyclicprefix (CP). A base station may send (e.g., transmit) to and/or receivefrom a wireless device via a number of subcarriers 703 in a carrier. Abandwidth occupied by a number of subcarriers 703 (e.g., transmissionbandwidth) may be smaller than the channel bandwidth 700 of a carrier,for example, due to guard bands 704 and 705. Guard bands 704 and 705 maybe used to reduce interference to and from one or more neighborcarriers. A number of subcarriers (e.g., transmission bandwidth) in acarrier may depend on the channel bandwidth of the carrier and/or thesubcarrier spacing. A transmission bandwidth, for a carrier with a 20MHz channel bandwidth and a 15 kHz subcarrier spacing, may be in numberof 1024 subcarriers.

A base station and a wireless device may communicate with multiplecomponent carriers (CCs), for example, if configured with CA. Differentcomponent carriers may have different bandwidth and/or differentsubcarrier spacing, for example, if CA is supported. A base station maysend (e.g., transmit) a first type of service to a wireless device via afirst component carrier. The base station may send (e.g., transmit) asecond type of service to the wireless device via a second componentcarrier. Different types of services may have different servicerequirements (e.g., data rate, latency, reliability), which may besuitable for transmission via different component carriers havingdifferent subcarrier spacing and/or different bandwidth.

FIG. 7B shows examples of component carriers. A first component carriermay comprise a first number of subcarriers 706 having a first subcarrierspacing 709. A second component carrier may comprise a second number ofsubcarriers 707 having a second subcarrier spacing 710. A thirdcomponent carrier may comprise a third number of subcarriers 708 havinga third subcarrier spacing 711. Carriers in a multicarrier OFDMcommunication system may be contiguous carriers, non-contiguouscarriers, or a combination of both contiguous and non-contiguouscarriers.

FIG. 8 shows an example of OFDM radio resources. A carrier may have atransmission bandwidth 801. A resource grid may be in a structure offrequency domain 802 and time domain 803. A resource grid may comprise afirst number of OFDM symbols in a subframe and a second number ofresource blocks, starting from a common resource block indicated byhigher-layer signaling (e.g., RRC signaling), for a transmissionnumerology and a carrier. In a resource grid, a resource element 805 maycomprise a resource unit that may be identified by a subcarrier indexand a symbol index. A subframe may comprise a first number of OFDMsymbols 807 that may depend on a numerology associated with a carrier. Asubframe may have 14 OFDM symbols for a carrier, for example, if asubcarrier spacing of a numerology of a carrier is 15 kHz. A subframemay have 28 OFDM symbols, for example, if a subcarrier spacing of anumerology is 30 kHz. A subframe may have 56 OFDM symbols, for example,if a subcarrier spacing of a numerology is 60 kHz. A subcarrier spacingof a numerology may comprise any other frequency. A second number ofresource blocks comprised in a resource grid of a carrier may depend ona bandwidth and a numerology of the carrier.

A resource block 806 may comprise 12 subcarriers. Multiple resourceblocks may be grouped into a Resource Block Group (RBG) 804. A size of aRBG may depend on at least one of: a RRC message indicating a RBG sizeconfiguration; a size of a carrier bandwidth; and/or a size of a BWP ofa carrier. A carrier may comprise multiple BWPs. A first BWP of acarrier may have a different frequency location and/or a differentbandwidth from a second BWP of the carrier.

A base station may send (e.g., transmit), to a wireless device, adownlink control information comprising a downlink or uplink resourceblock assignment. A base station may send (e.g., transmit) to and/orreceive from, a wireless device, data packets (e.g., TBs). The datapackets may be scheduled on and transmitted via one or more resourceblocks and one or more slots indicated by parameters in downlink controlinformation and/or RRC message(s). A starting symbol relative to a firstslot of the one or more slots may be indicated to the wireless device. Abase station may send (e.g., transmit) to and/or receive from, awireless device, data packets. The data packets may be scheduled fortransmission on one or more RBGs and in one or more slots.

A base station may send (e.g., transmit), to a wireless device, downlinkcontrol information comprising a downlink assignment. The base stationmay send (e.g., transmit) the DCI via one or more PDCCHs. The downlinkassignment may comprise parameters indicating at least one of amodulation and coding format; resource allocation; and/or HARQinformation related to the DL-SCH. The resource allocation may compriseparameters of resource block allocation; and/or slot allocation. A basestation may allocate (e.g., dynamically) resources to a wireless device,for example, via a Cell-Radio Network Temporary Identifier (C-RNTI) onone or more PDCCHs. The wireless device may monitor the one or morePDCCHs, for example, in order to find possible allocation if itsdownlink reception is enabled. The wireless device may receive one ormore downlink data packets on one or more PDSCH scheduled by the one ormore PDCCHs, for example, if the wireless device successfully detectsthe one or more PDCCHs.

A base station may allocate Configured Scheduling (CS) resources fordown link transmission to a wireless device. The base station may send(e.g., transmit) one or more RRC messages indicating a periodicity ofthe CS grant. The base station may send (e.g., transmit) DCI via a PDCCHaddressed to a Configured Scheduling-RNTI (CS-RNTI) activating the CSresources. The DCI may comprise parameters indicating that the downlinkgrant is a CS grant. The CS grant may be implicitly reused according tothe periodicity defined by the one or more RRC messages. The CS grantmay be implicitly reused, for example, until deactivated.

A base station may send (e.g., transmit), to a wireless device via oneor more PDCCHs, downlink control information comprising an uplink grant.The uplink grant may comprise parameters indicating at least one of amodulation and coding format; a resource allocation; and/or HARQinformation related to the UL-SCH. The resource allocation may compriseparameters of resource block allocation; and/or slot allocation. Thebase station may dynamically allocate resources to the wireless devicevia a C-RNTI on one or more PDCCHs. The wireless device may monitor theone or more PDCCHs, for example, in order to find possible resourceallocation. The wireless device may send (e.g., transmit) one or moreuplink data packets via one or more PUSCH scheduled by the one or morePDCCHs, for example, if the wireless device successfully detects the oneor more PDCCHs.

The base station may allocate CS resources for uplink data transmissionto a wireless device. The base station may transmit one or more RRCmessages indicating a periodicity of the CS grant. The base station maysend (e.g., transmit) DCI via a PDCCH addressed to a CS-RNTI to activatethe CS resources. The DCI may comprise parameters indicating that theuplink grant is a CS grant. The CS grant may be implicitly reusedaccording to the periodicity defined by the one or more RRC message, TheCS grant may be implicitly reused, for example, until deactivated.

A base station may send (e.g., transmit) DCI and/or control signalingvia a PDCCH. The DCI may comprise a format of a plurality of formats.The DCI may comprise downlink and/or uplink scheduling information(e.g., resource allocation information, HARQ related parameters, MCS),request(s) for CSI (e.g., aperiodic CQI reports), request(s) for an SRS,uplink power control commands for one or more cells, one or more timinginformation (e.g., TB transmission/reception timing, HARQ feedbacktiming, etc.), and/or the like. The DCI may indicate an uplink grantcomprising transmission parameters for one or more TBs. The DCI mayindicate a downlink assignment indicating parameters for receiving oneor more TBs. The DCI may be used by the base station to initiate acontention-free RA at the wireless device. The base station may send(e.g., transmit) DCI comprising a slot format indicator (SFI) indicatinga slot format. The base station may send (e.g., transmit) DCI comprisinga preemption indication indicating the PRB(s) and/or OFDM symbol(s) inwhich a wireless device may assume no transmission is intended for thewireless device. The base station may send (e.g., transmit) DCI forgroup power control of the PUCCH, the PUSCH, and/or an SRS. DCI maycorrespond to an RNTI. The wireless device may obtain an RNTI after orin response to completing the initial access (e.g., C-RNTI). The basestation may configure an RNTI for the wireless (e.g., CS-RNTI,TPC-CS-RNTI, TPC-PUCCH-RNTI, TPC-PUSCH-RNTI, TPC-SRS-RNTI, etc.). Thewireless device may determine (e.g., compute) an RNTI (e.g., thewireless device may determine the RA-RNTI based on resources used fortransmission of a preamble). An RNTI may have a pre-configured value(e.g., P-RNTI or SI-RNTI). The wireless device may monitor a groupcommon search space which may be used by the base station for sending(e.g., transmitting) DCIs that are intended for a group of wirelessdevices. A group common DCI may correspond to an RNTI which is commonlyconfigured for a group of wireless devices. The wireless device maymonitor a wireless device-specific search space. A wireless devicespecific DCI may correspond to an RNTI configured for the wirelessdevice.

A communications system (e.g., an NR system) may support a single beamoperation and/or a multi-beam operation. In a multi-beam operation, abase station may perform a downlink beam sweeping to provide coveragefor common control channels and/or downlink SS blocks, which maycomprise at least a PSS, a SSS, and/or PBCH. A wireless device maymeasure quality of a beam pair link using one or more RSs. One or moreSS blocks, or one or more CSI-RS resources (e.g., which may beassociated with a CSI-RS resource index (CRI)), and/or one or moreDM-RSs of a PBCH, may be used as an RS for measuring a quality of a beampair link. The quality of a beam pair link may be based on a referencesignal received power (RSRP) value, a reference signal received quality(RSRQ) value, and/or a CSI value measured on RS resources. The basestation may indicate whether an RS resource, used for measuring a beampair link quality, is quasi-co-located (QCLed) with DM-RSs of a controlchannel. An RS resource and DM-RSs of a control channel may be calledQCLed, for example, if channel characteristics from a transmission on anRS to a wireless device, and that from a transmission on a controlchannel to a wireless device, are similar or the same under a configuredcriterion. In a multi-beam operation, a wireless device may perform anuplink beam sweeping to access a cell.

A wireless device may be configured to monitor a PDCCH on one or morebeam pair links simultaneously, for example, depending on a capabilityof the wireless device. This monitoring may increase robustness againstbeam pair link blocking. A base station may send (e.g., transmit) one ormore messages to configure the wireless device to monitor the PDCCH onone or more beam pair links in different PDCCH OFDM symbols. A basestation may send (e.g., transmit) higher layer signaling (e.g., RRCsignaling) and/or a MAC CE comprising parameters related to the Rx beamsetting of the wireless device for monitoring the PDCCH on one or morebeam pair links. The base station may send (e.g., transmit) anindication of a spatial QCL assumption between an DL RS antenna port(s)(e.g., a cell-specific CSI-RS, a wireless device-specific CSI-RS, an SSblock, and/or a PBCH with or without DM-RSs of the PBCH) and/or DL RSantenna port(s) for demodulation of a DL control channel. Signaling forbeam indication for a PDCCH may comprise MAC CE signaling, RRCsignaling, DCI signaling, and/or specification-transparent and/orimplicit method, and/or any combination of signaling methods.

A base station may indicate spatial QCL parameters between DL RS antennaport(s) and DM-RS antenna port(s) of a DL data channel, for example, forreception of a unicast DL data channel. The base station may send (e.g.,transmit) DCI (e.g., downlink grants) comprising information indicatingthe RS antenna port(s). The information may indicate RS antenna port(s)that may be QCL-ed with the DM-RS antenna port(s). A different set ofDM-RS antenna port(s) for a DL data channel may be indicated as QCL witha different set of the RS antenna port(s).

FIG. 9A shows an example of beam sweeping in a DL channel. In anRRC_INACTIVE state or RRC_IDLE state, a wireless device may assume thatSS blocks form an SS burst 940, and an SS burst set 950. The SS burstset 950 may have a given periodicity. A base station 120 may send (e.g.,transmit) SS blocks in multiple beams, together forming a SS burst 940,for example, in a multi-beam operation. One or more SS blocks may besent (e.g., transmitted) on one beam. If multiple SS bursts 940 aretransmitted with multiple beams, SS bursts together may form SS burstset 950.

A wireless device may use CSI-RS for estimating a beam quality of a linkbetween a wireless device and a base station, for example, in the multibeam operation. A beam may be associated with a CSI-RS. A wirelessdevice may (e.g., based on a RSRP measurement on CSI-RS) report a beamindex, which may be indicated in a CRI for downlink beam selectionand/or associated with an RSRP value of a beam. A CSI-RS may be sent(e.g., transmitted) on a CSI-RS resource, which may comprise at leastone of: one or more antenna ports and/or one or more time and/orfrequency radio resources. A CSI-RS resource may be configured in acell-specific way such as by common RRC signaling, or in a wirelessdevice-specific way such as by dedicated RRC signaling and/or L1/L2signaling. Multiple wireless devices covered by a cell may measure acell-specific CSI-RS resource. A dedicated subset of wireless devicescovered by a cell may measure a wireless device-specific CSI-RSresource.

A CSI-RS resource may be sent (e.g., transmitted) periodically, usingaperiodic transmission, or using a multi-shot or semi-persistenttransmission. In a periodic transmission in FIG. 9A, a base station 120may send (e.g., transmit) configured CSI-RS resources 940 periodicallyusing a configured periodicity in a time domain. In an aperiodictransmission, a configured CSI-RS resource may be sent (e.g.,transmitted) in a dedicated time slot. In a multi-shot and/orsemi-persistent transmission, a configured CSI-RS resource may be sent(e.g., transmitted) within a configured period. Beams used for CSI-RStransmission may have a different beam width than beams used forSS-blocks transmission.

FIG. 9B shows an example of a beam management procedure, such as a newradio network. The base station 120 and/or the wireless device 110 mayperform a downlink L1/L2 beam management procedure. One or more of thefollowing downlink L1/L2 beam management procedures may be performedwithin one or more wireless devices 110 and one or more base stations120. A P1 procedure 910 may be used to enable the wireless device 110 tomeasure one or more Transmission (Tx) beams associated with the basestation 120, for example, to support a selection of a first set of Txbeams associated with the base station 120 and a first set of Rx beam(s)associated with the wireless device 110. A base station 120 may sweep aset of different Tx beams, for example, for beamforming at a basestation 120 (such as shown in the top row, in a counter-clockwisedirection). A wireless device 110 may sweep a set of different Rx beams,for example, for beamforming at a wireless device 110 (such as shown inthe bottom row, in a clockwise direction). A P2 procedure 920 may beused to enable a wireless device 110 to measure one or more Tx beamsassociated with a base station 120, for example, to possibly change afirst set of Tx beams associated with a base station 120. A P2 procedure920 may be performed on a possibly smaller set of beams (e.g., for beamrefinement) than in the P1 procedure 910. A P2 procedure 920 may be aspecial example of a P1 procedure 910. A P3 procedure 930 may be used toenable a wireless device 110 to measure at least one Tx beam associatedwith a base station 120, for example, to change a first set of Rx beamsassociated with a wireless device 110.

A wireless device 110 may send (e.g., transmit) one or more beammanagement reports to a base station 120. In one or more beam managementreports, a wireless device 110 may indicate one or more beam pairquality parameters comprising one or more of: a beam identification; anRSRP; a Precoding Matrix Indicator (PMI), Channel Quality Indicator(CQI), and/or Rank Indicator (RI) of a subset of configured beams. Basedon one or more beam management reports, the base station 120 may send(e.g., transmit) to a wireless device 110 a signal indicating that oneor more beam pair links are one or more serving beams. The base station120 may send (e.g., transmit) the PDCCH and the PDSCH for a wirelessdevice 110 using one or more serving beams.

A communications network (e.g., a new radio network) may support aBandwidth Adaptation (BA). Receive and/or transmit bandwidths that maybe configured for a wireless device using a BA may not be large. Receiveand/or transmit bandwidth may not be as large as a bandwidth of a cell.Receive and/or transmit bandwidths may be adjustable. A wireless devicemay change receive and/or transmit bandwidths, for example, to reduce(e.g., shrink) the bandwidth(s) at (e.g., during) a period of lowactivity such as to save power. A wireless device may change a locationof receive and/or transmit bandwidths in a frequency domain, forexample, to increase scheduling flexibility. A wireless device maychange a subcarrier spacing, for example, to allow different services.

A Bandwidth Part (BWP) may comprise a subset of a total cell bandwidthof a cell. A base station may configure a wireless device with one ormore BWPs, for example, to achieve a BA. A base station may indicate, toa wireless device, which of the one or more (configured) BWPs is anactive BWP.

FIG. 10 shows an example of BWP configurations. BWPs may be configuredas follows: BWP1 (1010 and 1050) with a width of 40 MHz and subcarrierspacing of 15 kHz; BWP2 (1020 and 1040) with a width of 10 MHz andsubcarrier spacing of 15 kHz; BWP3 1030 with a width of 20 MHz andsubcarrier spacing of 60 kHz. Any number of BWP configurations maycomprise any other width and subcarrier spacing combination.

A wireless device, configured for operation in one or more BWPs of acell, may be configured by one or more higher layers (e.g., RRC layer).The wireless device may be configured for a cell with: a set of one ormore BWPs (e.g., at most four BWPs) for reception (e.g., a DL BWP set)in a DL bandwidth by at least one parameter DL-BWP; and a set of one ormore BWPs (e.g., at most four BWPs) for transmissions (e.g., UL BWP set)in an UL bandwidth by at least one parameter UL-BWP.

A base station may configure a wireless device with one or more UL andDL BWP pairs, for example, to enable BA on the PCell. To enable BA onSCells (e.g., for CA), a base station may configure a wireless device atleast with one or more DL BWPs (e.g., there may be none in an UL).

An initial active DL BWP may comprise at least one of a location andnumber of contiguous PRBs, a subcarrier spacing, or a cyclic prefix, forexample, for a CORESETs for at least one common search space. Foroperation on the PCell, one or more higher layer parameters may indicateat least one initial UL BWP for a RA procedure. If a wireless device isconfigured with a secondary carrier on a primary cell, the wirelessdevice may be configured with an initial BWP for RA procedure on asecondary carrier.

A wireless device may expect that a center frequency for a DL BWP may besame as a center frequency for a UL BWP, for example, for unpairedspectrum operation. A base station may semi-statically configure awireless device for a cell with one or more parameters, for example, fora DL BWP or an UL BWP in a set of one or more DL BWPs or one or more ULBWPs, respectively. The one or more parameters may indicate one or moreof following: a subcarrier spacing; a cyclic prefix; a number ofcontiguous PRBs; an index in the set of one or more DL BWPs and/or oneor more UL BWPs; a link between a DL BWP and an UL BWP from a set ofconfigured DL BWPs and UL BWPs; a DCI detection to a PDSCH receptiontiming; a PDSCH reception to a HARQ-ACK transmission timing value; a DCIdetection to a PUSCH transmission timing value; and/or an offset of afirst PRB of a DL bandwidth or an UL bandwidth, respectively, relativeto a first PRB of a bandwidth.

For a DL BWP in a set of one or more DL BWPs on a PCell, a base stationmay configure a wireless device with one or more control resource setsfor at least one type of common search space and/or one wirelessdevice-specific search space. A base station may not configure awireless device without a common search space on a PCell, or on aPSCell, in an active DL BWP. For an UL BWP in a set of one or more ULBWPs, a base station may configure a wireless device with one or moreresource sets for one or more PUCCH transmissions.

DCI may comprise a BWP indicator field. The BWP indicator field valuemay indicate an active DL BWP, from a configured DL BWP set, for one ormore DL receptions. The BWP indicator field value may indicate an activeUL BWP, from a configured UL BWP set, for one or more UL transmissions.

For a PCell, a base station may semi-statically configure a wirelessdevice with a default DL BWP among configured DL BWPs. If a wirelessdevice is not provided a default DL BWP, a default BWP may be an initialactive DL BWP.

A base station may configure a wireless device with a timer value for aPCell. A wireless device may start a timer (e.g., a BWP inactivitytimer), for example, if a wireless device detects DCI indicating anactive DL BWP, other than a default DL BWP, for a paired spectrumoperation, and/or if a wireless device detects DCI indicating an activeDL BWP or UL BWP, other than a default DL BWP or UL BWP, for an unpairedspectrum operation. The wireless device may increment the timer by aninterval of a first value (e.g., the first value may be 1 millisecond,0.5 milliseconds, or any other time duration), for example, if thewireless device does not detect DCI at (e.g., during) the interval for apaired spectrum operation or for an unpaired spectrum operation. Thetimer may expire at a time that the timer is equal to the timer value. Awireless device may switch to the default DL BWP from an active DL BWP,for example, if the timer expires.

A base station may semi-statically configure a wireless device with oneor more BWPs. A wireless device may switch an active BWP from a firstBWP to a second BWP, for example, after or in response to receiving DCIindicating the second BWP as an active BWP, and/or after or in responseto an expiry of BWP inactivity timer (e.g., the second BWP may be adefault BWP). FIG. 10 shows an example of three BWPs configured, BWP1(1010 and 1050), BWP2 (1020 and 1040), and BWP3 (1030). BWP2 (1020 and1040) may be a default BWP. BWP1 (1010) may be an initial active BWP. Awireless device may switch an active BWP from BWP1 1010 to BWP2 1020,for example, after or in response to an expiry of the BWP inactivitytimer. A wireless device may switch an active BWP from BWP2 1020 to BWP31030, for example, after or in response to receiving DCI indicating BWP31030 as an active BWP. Switching an active BWP from BWP3 1030 to BWP21040 and/or from BWP2 1040 to BWP1 1050 may be after or in response toreceiving DCI indicating an active BWP, and/or after or in response toan expiry of BWP inactivity timer.

Wireless device procedures on a secondary cell may be same as on aprimary cell using the timer value for the secondary cell and thedefault DL BWP for the secondary cell, for example, if a wireless deviceis configured for a secondary cell with a default DL BWP amongconfigured DL BWPs and a timer value. A wireless device may use anindicated DL BWP and an indicated UL BWP on a secondary cell as arespective first active DL BWP and first active UL BWP on a secondarycell or carrier, for example, if a base station configures a wirelessdevice with a first active DL BWP and a first active UL BWP on asecondary cell or carrier.

FIG. 11A and FIG. 11B show packet flows using a multi connectivity(e.g., dual connectivity, multi connectivity, tight interworking, and/orthe like). FIG. 11A shows an example of a protocol structure of awireless device 110 (e.g., UE) with CA and/or multi connectivity. FIG.11B shows an example of a protocol structure of multiple base stationswith CA and/or multi connectivity. The multiple base stations maycomprise a master node, MN 1130 (e.g., a master node, a master basestation, a master gNB, a master eNB, and/or the like) and a secondarynode, SN 1150 (e.g., a secondary node, a secondary base station, asecondary gNB, a secondary eNB, and/or the like). A master node 1130 anda secondary node 1150 may co-work to communicate with a wireless device110.

If multi connectivity is configured for a wireless device 110, thewireless device 110, which may support multiple reception and/ortransmission functions in an RRC connected state, may be configured toutilize radio resources provided by multiple schedulers of a multiplebase stations. Multiple base stations may be inter-connected via anon-ideal or ideal backhaul (e.g., Xn interface, X2 interface, and/orthe like). A base station involved in multi connectivity for a certainwireless device may perform at least one of two different roles: a basestation may act as a master base station or act as a secondary basestation. In multi connectivity, a wireless device may be connected toone master base station and one or more secondary base stations. Amaster base station (e.g., the MN 1130) may provide a master cell group(MCG) comprising a primary cell and/or one or more secondary cells for awireless device (e.g., the wireless device 110). A secondary basestation (e.g., the SN 1150) may provide a secondary cell group (SCG)comprising a primary secondary cell (PSCell) and/or one or moresecondary cells for a wireless device (e.g., the wireless device 110).

In multi connectivity, a radio protocol architecture that a bearer usesmay depend on how a bearer is setup. Three different types of bearersetup options may be supported: an MCG bearer, an SCG bearer, and/or asplit bearer. A wireless device may receive and/or send (e.g., transmit)packets of an MCG bearer via one or more cells of the MCG. A wirelessdevice may receive and/or send (e.g., transmit) packets of an SCG bearervia one or more cells of an SCG. Multi-connectivity may indicate havingat least one bearer configured to use radio resources provided by thesecondary base station. Multi-connectivity may or may not be configuredand/or implemented.

A wireless device (e.g., wireless device 110) may send (e.g., transmit)and/or receive:

packets of an MCG bearer via an SDAP layer (e.g., SDAP 1110), a PDCPlayer (e.g., NR PDCP 1111), an RLC layer (e.g., MN RLC 1114), and a MAClayer (e.g., MN MAC 1118); packets of a split bearer via an SDAP layer(e.g., SDAP 1110), a PDCP layer (e.g., NR PDCP 1112), one of a master orsecondary RLC layer (e.g., MN RLC 1115, SN RLC 1116), and one of amaster or secondary MAC layer (e.g., MN MAC 1118, SN MAC 1119); and/orpackets of an SCG bearer via an SDAP layer (e.g., SDAP 1110), a PDCPlayer (e.g., NR PDCP 1113), an RLC layer (e.g., SN RLC 1117), and a MAClayer (e.g., MN MAC 1119).

A master base station (e.g., MN 1130) and/or a secondary base station(e.g., SN 1150) may send (e.g., transmit) and/or receive: packets of anMCG bearer via a master or secondary node SDAP layer (e.g., SDAP 1120,SDAP 1140), a master or secondary node PDCP layer (e.g., NR PDCP 1121,NR PDCP 1142), a master node RLC layer (e.g., MN RLC 1124, MN RLC 1125),and a master node MAC layer (e.g., MN MAC 1128); packets of an SCGbearer via a master or secondary node SDAP layer (e.g., SDAP 1120, SDAP1140), a master or secondary node PDCP layer (e.g., NR PDCP 1122, NRPDCP 1143), a secondary node RLC layer (e.g., SN RLC 1146, SN RLC 1147),and a secondary node MAC layer (e.g., SN MAC 1148); packets of a splitbearer via a master or secondary node SDAP layer (e.g., SDAP 1120, SDAP1140), a master or secondary node PDCP layer (e.g., NR PDCP 1123, NRPDCP 1141), a master or secondary node RLC layer (e.g., MN RLC 1126, SNRLC 1144, SN RLC 1145, MN RLC 1127), and a master or secondary node MAClayer (e.g., MN MAC 1128, SN MAC 1148).

In multi connectivity, a wireless device may configure multiple MACentities, such as one MAC entity (e.g., MN MAC 1118) for a master basestation, and other MAC entities (e.g., SN MAC 1119) for a secondary basestation. In multi-connectivity, a configured set of serving cells for awireless device may comprise two subsets: an MCG comprising servingcells of a master base station, and SCGs comprising serving cells of asecondary base station. For an SCG, one or more of followingconfigurations may be used. At least one cell of an SCG may have aconfigured UL CC and at least one cell of a SCG, named as primarysecondary cell (e.g., PSCell, PCell of SCG, PCell), and may beconfigured with PUCCH resources. If an SCG is configured, there may beat least one SCG bearer or one split bearer. After or upon detection ofa physical layer problem or a RA problem on a PSCell, or a number of NRRLC retransmissions has been reached associated with the SCG, or afteror upon detection of an access problem on a PSCell associated with(e.g., during) a SCG addition or an SCG change: an RRC connectionre-establishment procedure may not be triggered, UL transmissionstowards cells of an SCG may be stopped, a master base station may beinformed by a wireless device of a SCG failure type, a DL data transferover a master base station may be maintained (e.g., for a split bearer).An NR RLC acknowledged mode (AM) bearer may be configured for a splitbearer. A PCell and/or a PSCell may not be de-activated. A PSCell may bechanged with a SCG change procedure (e.g., with security key change anda RACH procedure). A bearer type change between a split bearer and a SCGbearer, and/or simultaneous configuration of a SCG and a split bearer,may or may not be supported.

With respect to interactions between a master base station and asecondary base stations for multi-connectivity, one or more of thefollowing may be used. A master base station and/or a secondary basestation may maintain RRM measurement configurations of a wirelessdevice. A master base station may determine (e.g., based on receivedmeasurement reports, traffic conditions, and/or bearer types) to requesta secondary base station to provide additional resources (e.g., servingcells) for a wireless device. After or upon receiving a request from amaster base station, a secondary base station may create and/or modify acontainer that may result in a configuration of additional serving cellsfor a wireless device (or decide that the secondary base station has noresource available to do so). For a wireless device capabilitycoordination, a master base station may provide (e.g., all or a part of)an AS configuration and wireless device capabilities to a secondary basestation. A master base station and a secondary base station may exchangeinformation about a wireless device configuration such as by using RRCcontainers (e.g., inter-node messages) carried via Xn messages. Asecondary base station may initiate a reconfiguration of the secondarybase station existing serving cells (e.g., PUCCH towards the secondarybase station). A secondary base station may decide which cell is aPSCell within a SCG. A master base station may or may not change contentof RRC configurations provided by a secondary base station. A masterbase station may provide recent (and/or the latest) measurement resultsfor SCG cell(s), for example, if an SCG addition and/or an SCG SCelladdition occurs. A master base station and secondary base stations mayreceive information of SFN and/or subframe offset of each other from anOAM and/or via an Xn interface (e.g., for a purpose of DRX alignmentand/or identification of a measurement gap). Dedicated RRC signaling maybe used for sending required system information of a cell as for CA, forexample, if adding a new SCG SCell, except for an SFN acquired from anMIB of a PSCell of a SCG.

FIG. 12 shows an example of a RA procedure. One or more events maytrigger a RA procedure. For example, one or more events may be at leastone of following: initial access from RRC IDLE, RRC connectionre-establishment procedure, handover, DL or UL data arrival in (e.g.,during) a state of RRC CONNECTED (e.g., if UL synchronization status isnon-synchronized), transition from RRC Inactive, and/or request forother system information. A PDCCH order, a MAC entity, and/or a beamfailure indication may initiate a RA procedure.

A RA procedure may comprise or be one of at least a contention based RAprocedure and/or a contention free RA procedure. A contention based RAprocedure may comprise one or more Msg 1 1220 transmissions, one or moreMsg2 1230 transmissions, one or more Msg3 1240 transmissions, andcontention resolution 1250. A contention free RA procedure may compriseone or more Msg 1 1220 transmissions and one or more Msg2 1230transmissions. One or more of Msg 1 1220, Msg 2 1230, Msg 3 1240, and/orcontention resolution 1250 may be transmitted in the same step. Atwo-step RA procedure, for example, may comprise a first transmission(e.g., Msg A) and a second transmission (e.g., Msg B). The firsttransmission (e.g., Msg A) may comprise transmitting, by a wirelessdevice (e.g., wireless device 110) to a base station (e.g., base station120), one or more messages indicating an equivalent and/or similarcontents of Msg1 1220 and Msg3 1240 of a four-step RA procedure. Thesecond transmission (e.g., Msg B) may comprise transmitting, by the basestation (e.g., base station 120) to a wireless device (e.g., wirelessdevice 110) after or in response to the first message, one or moremessages indicating an equivalent and/or similar content of Msg2 1230and contention resolution 1250 of a four-step RA procedure.

A base station may send (e.g., transmit, unicast, multicast, broadcast,etc.), to a wireless device, a RACH configuration 1210 via one or morebeams. The RACH configuration 1210 may comprise one or more parametersindicating at least one of following: an available set of PRACHresources for a transmission of a random access preamble (RAP), initialpreamble power (e.g., RAP initial received target power), an RSRPthreshold for a selection of a SS block and corresponding PRACHresource, a power-ramping factor (e.g., RAP power ramping step), a RAPindex, a maximum number of preamble transmissions, preamble group A andgroup B, a threshold (e.g., message size) to determine the groups ofRAPs, a set of one or more RAPs for a system information request andcorresponding PRACH resource(s) (e.g., if any), a set of one or moreRAPs for a beam failure recovery request and corresponding PRACHresource(s) (e.g., if any), a time window to monitor RAR(s), a timewindow to monitor response(s) on a beam failure recovery request, and/ora contention resolution timer.

The Msg1 1220 may comprise one or more transmissions of a RAP. For acontention based RA procedure, a wireless device may select an SS blockwith an RSRP above the RSRP threshold. If RAPs group B exists, awireless device may select one or more RAPs from a group A or a group B,for example, depending on a potential Msg3 1240 size. If a RAPs group Bdoes not exist, a wireless device may select the one or more RAPs from agroup A. A wireless device may select a RAP index randomly (e.g., withequal probability or a normal distribution) from one or more RAPsassociated with a selected group. If a base station semi-staticallyconfigures a wireless device with an association between RAPs and SSblocks, the wireless device may select a RAP index randomly with equalprobability from one or more RAPs associated with a selected SS blockand a selected group.

A wireless device may initiate a contention free RA procedure, forexample, based on a beam failure indication from a lower layer. A basestation may semi-statically configure a wireless device with one or morecontention free PRACH resources for a beam failure recovery requestassociated with at least one of SS blocks and/or CSI-RSs. A wirelessdevice may select a RAP index corresponding to a selected SS block or aCSI-RS from a set of one or more RAPs for a beam failure recoveryrequest, for example, if at least one of the SS blocks with an RSRPabove a first RSRP threshold among associated SS blocks is available,and/or if at least one of CSI-RSs with a RSRP above a second RSRPthreshold among associated CSI-RSs is available.

A wireless device may receive, from a base station, a RAP index viaPDCCH or RRC for a contention free RA procedure. The wireless device mayselect a RAP index, for example, if a base station does not configure awireless device with at least one contention free PRACH resourceassociated with SS blocks or CSI-RS. The wireless device may select theat least one SS block and/or select a RAP corresponding to the at leastone SS block, for example, if a base station configures the wirelessdevice with one or more contention free PRACH resources associated withSS blocks and/or if at least one SS block with a RSRP above a first RSRPthreshold among associated SS blocks is available. The wireless devicemay select the at least one CSI-RS and/or select a RAP corresponding tothe at least one CSI-RS, for example, if a base station configures awireless device with one or more contention free PRACH resourcesassociated with CSI-RSs and/or if at least one CSI-RS with a RSRP abovea second RSPR threshold among the associated CSI-RSs is available.

A wireless device may perform one or more Msg1 1220 transmissions, forexample, by sending (e.g., transmitting) the selected RAP. The wirelessdevice may determine a PRACH occasion from one or more PRACH occasionscorresponding to a selected SS block, for example, if the wirelessdevice selects an SS block and is configured with an association betweenone or more PRACH occasions and/or one or more SS blocks. The wirelessdevice may determine a PRACH occasion from one or more PRACH occasionscorresponding to a selected CSI-RS, for example, if the wireless deviceselects a CSI-RS and is configured with an association between one ormore PRACH occasions and one or more CSI-RSs. The wireless device maysend (e.g., transmit), to a base station, a selected RAP via a selectedPRACH occasions. The wireless device may determine a transmit power fora transmission of a selected RAP at least based on an initial preamblepower and a power-ramping factor. The wireless device may determine anRA-RNTI associated with a selected PRACH occasion in which a selectedRAP is sent (e.g., transmitted). The wireless device may not determinean RA-RNTI for a beam failure recovery request. The wireless device maydetermine an RA-RNTI at least based on an index of a first OFDM symbol,an index of a first slot of a selected PRACH occasions, and/or an uplinkcarrier index for a transmission of Msg1 1220.

A wireless device may receive, from a base station, a RAR, Msg 2 1230.The wireless device may start a time window (e.g., ra-ResponseWindow) tomonitor a RAR. For a beam failure recovery procedure, the base stationmay configure the wireless device with a different time window (e.g.,bfr-ResponseWindow) to monitor response to on a beam failure recoveryrequest. The wireless device may start a time window (e.g.,ra-ResponseWindow or bfr-ResponseWindow) at a start of a first PDCCHoccasion, for example, after a fixed duration of one or more symbolsfrom an end of a preamble transmission. If the wireless device sends(e.g., transmits) multiple preambles, the wireless device may start atime window at a start of a first PDCCH occasion after a fixed durationof one or more symbols from an end of a first preamble transmission. Thewireless device may monitor a PDCCH of a cell for at least one RARidentified by a RA-RNTI, or for at least one response to a beam failurerecovery request identified by a C-RNTI, at a time that a timer for atime window is running.

A wireless device may determine that a reception of RAR is successful,for example, if at least one RAR comprises a random access preambleidentifier (RAPID) corresponding to a RAP sent (e.g., transmitted) bythe wireless device. The wireless device may determine that thecontention free RA procedure is successfully completed, for example, ifa reception of a RAR is successful. The wireless device may determinethat a contention free RA procedure is successfully complete, forexample, if a contention free RA procedure is triggered for a beamfailure recovery request and if a PDCCH transmission is addressed to aC-RNTI. The wireless device may determine that the RA procedure issuccessfully completed, and may indicate a reception of anacknowledgement for a system information request to upper layers, forexample, if at least one RAR comprises a RAPID. The wireless device maystop sending (e.g., transmitting) remaining preambles (if any) after orin response to a successful reception of a corresponding RAR, forexample, if the wireless device has signaled multiple preambletransmissions.

The wireless device may perform one or more Msg 3 1240 transmissions,for example, after or in response to a successful reception of RAR(e.g., for a contention based RA procedure). The wireless device mayadjust an uplink transmission timing, for example, based on a timingadvanced command indicated by a RAR. The wireless device may send (e.g.,transmit) one or more TBs, for example, based on an uplink grantindicated by a RAR. Subcarrier spacing for PUSCH transmission for Msg31240 may be provided by at least one higher layer (e.g., RRC) parameter.The wireless device may send (e.g., transmit) a RAP via a PRACH, andMsg3 1240 via PUSCH, on the same cell. A base station may indicate an ULBWP for a PUSCH transmission of Msg3 1240 via system information block.The wireless device may use HARQ for a retransmission of Msg 3 1240.

Multiple wireless devices may perform Msg 1 1220, for example, bysending (e.g., transmitting) the same preamble to a base station. Themultiple wireless devices may receive, from the base station, the sameRAR comprising an identity (e.g., TC-RNTI). Contention resolution (e.g.,comprising the wireless device 110 receiving contention resolution 1250)may be used to increase the likelihood that a wireless device does notincorrectly use an identity of another wireless device. The contentionresolution 1250 may be based on, for example, a C-RNTI on a PDCCH,and/or a wireless device contention resolution identity on a DL-SCH. Ifa base station assigns a C-RNTI to a wireless device, the wirelessdevice may perform contention resolution (e.g., comprising receivingcontention resolution 1250), for example, based on a reception of aPDCCH transmission that is addressed to the C-RNTI. The wireless devicemay determine that contention resolution is successful, and/or that a RAprocedure is successfully completed, for example, after or in responseto detecting a C-RNTI on a PDCCH. If a wireless device has no validC-RNTI, a contention resolution may be addressed by using a TC-RNTI. Ifa MAC PDU is successfully decoded and a MAC PDU comprises a wirelessdevice contention resolution identity MAC CE that matches or otherwisecorresponds with the CCCH SDU sent (e.g., transmitted) in Msg3 1250, thewireless device may determine that the contention resolution (e.g.,comprising contention resolution 1250) is successful and/or the wirelessdevice may determine that the RA procedure is successfully completed.

RA procedures may be used to establish communications between a wirelessdevice and a base station associated with a cell. A four-step RAprocedure (e.g., such as shown in FIG. 12 and described above) may havean associated latency. The associated latency for the four-step RAprocedure may be a minimum of a quantity (e.g., fourteen or any otherquantity) of transmission time intervals (TTIs). A TTI may be anytransmission time interval or other time duration. A minimum latency offourteen TTIs may comprise, for example, three TTIs after a message fromstep 1 1220 of a four-step RA procedure, one TTI for a message from step2 1230 of a four-step RA procedure, five TTIs after the message fromstep 2, one TTI for a message from step 3 1240 of a four-step RAprocedure, three TTIs after the message from step 3, and one TTI for amessage from step 4 1250 of a four-step procedure (e.g.,3+1+5+1+3+1=14). The minimum latency may comprise any quantity of TTIs.Any of the above-references messages may comprise any quantity of TTIs.Reducing the number of steps in an RA procedure may reduce latency. Afour-step RA procedure may be reduced to a two-step RA procedure, forexample, by using parallel transmissions. A two-step RA procedure mayhave an associated latency. The associated latency for a two-step RAprocedure may be a minimum of four TTIs and which may be less than anassociated latency for a four-step RA procedure. A minimum latency offour TTIs may be a minimum of a quantity (e.g., four or any otherquantity) of TTIs. A minimum latency of four TTIs may comprise, forexample, three TTIs after a message from step 1 of a two-step RAprocedure, and one TTI for a message from step 2 of a two-step RAprocedure.

FIG. 13 shows an example structure for MAC entities. A wireless devicemay be configured to operate in a multi-connectivity mode. A wirelessdevice in RRC CONNECTED with multiple Rx/Tx may be configured to utilizeradio resources provided by multiple schedulers that may be located in aplurality of base stations. The plurality of base stations may beconnected via a non-ideal or ideal backhaul over the Xn interface. Abase station in a plurality of base stations may act as a master basestation or as a secondary base station. A wireless device may beconnected to and/or in communication with, for example, one master basestation and one or more secondary base stations. A wireless device maybe configured with multiple MAC entities, for example, one MAC entityfor a master base station, and one or more other MAC entities forsecondary base station(s). A configured set of serving cells for awireless device may comprise two subsets: an MCG comprising servingcells of a master base station, and one or more SCGs comprising servingcells of a secondary base station(s). FIG. 13 shows an example structurefor MAC entities in which a MCG and a SCG are configured for a wirelessdevice.

At least one cell in a SCG may have a configured UL CC. A cell of the atleast one cell may comprise a PSCell or a PCell of a SCG, or a PCell. APSCell may be configured with PUCCH resources. There may be at least oneSCG bearer, or one split bearer, for a SCG that is configured. After orupon detection of a physical layer problem or a RA problem on a PSCell,after or upon reaching a number of RLC retransmissions associated withthe SCG, and/or after or upon detection of an access problem on a PSCellassociated with (e.g., during) a SCG addition or a SCG change: an RRCconnection re-establishment procedure may not be triggered, ULtransmissions towards cells of a SCG may be stopped, and/or a masterbase station may be informed by a wireless device of a SCG failure typeand DL data transfer over a master base station may be maintained.

A MAC sublayer may provide services such as data transfer and radioresource allocation to upper layers (e.g., 1310 or 1320). A MAC sublayermay comprise a plurality of MAC entities (e.g., 1350 and 1360). A MACsublayer may provide data transfer services on logical channels. Toaccommodate different kinds of data transfer services, multiple types oflogical channels may be defined. A logical channel may support transferof a particular type of information. A logical channel type may bedefined by what type of information (e.g., control or data) istransferred. BCCH, PCCH, CCCH and/or DCCH may be control channels, andDTCH may be a traffic channel. A first MAC entity (e.g., 1310) mayprovide services on PCCH, BCCH, CCCH, DCCH, DTCH, and/or MAC controlelements. A second MAC entity (e.g., 1320) may provide services on BCCH,DCCH, DTCH, and/or MAC control elements.

A MAC sublayer may expect from a physical layer (e.g., 1330 or 1340)services such as data transfer services, signaling of HARQ feedback,and/or signaling of scheduling request or measurements (e.g., CQI). Indual connectivity, two MAC entities may be configured for a wirelessdevice: one for a MCG and one for a SCG. A MAC entity of a wirelessdevice may handle a plurality of transport channels. A first MAC entitymay handle first transport channels comprising a PCCH of a MCG, a firstBCH of the MCG, one or more first DL-SCHs of the MCG, one or more firstUL-SCHs of the MCG, and/or one or more first RACHs of the MCG. A secondMAC entity may handle second transport channels comprising a second BCHof a SCG, one or more second DL-SCHs of the SCG, one or more secondUL-SCHs of the SCG, and/or one or more second RACHs of the SCG.

If a MAC entity is configured with one or more SCells, there may bemultiple DL-SCHs, multiple UL-SCHs, and/or multiple RACHs per MACentity. There may be one DL-SCH and/or one UL-SCH on an SpCell. Theremay be one DL-SCH, zero or one UL-SCH, and/or zero or one RACH for anSCell. A DL-SCH may support receptions using different numerologiesand/or TTI duration within a MAC entity. A UL-SCH may supporttransmissions using different numerologies and/or TTI duration withinthe MAC entity.

A MAC sublayer may support different functions. The MAC sublayer maycontrol these functions with a control (e.g., Control 1355 and/orControl 1365) element. Functions performed by a MAC entity may compriseone or more of: mapping between logical channels and transport channels(e.g., in uplink or downlink), multiplexing (e.g., (De-) Multiplexing1352 and/or (De-) Multiplexing 1362) of MAC SDUs from one or differentlogical channels onto TBs to be delivered to the physical layer ontransport channels (e.g., in uplink), demultiplexing (e.g., (De-)Multiplexing 1352 and/or (De-) Multiplexing 1362) of MAC SDUs to one ordifferent logical channels from TBs delivered from the physical layer ontransport channels (e.g., in downlink), scheduling information reporting(e.g., in uplink), error correction through HARQ in uplink and/ordownlink (e.g., 1363), and logical channel prioritization in uplink(e.g., Logical Channel Prioritization 1351 and/or Logical ChannelPrioritization 1361). A MAC entity may handle a RA process (e.g., RandomAccess Control 1354 and/or Random Access Control 1364).

FIG. 14 shows an example of a RAN architecture comprising one or morebase stations. A protocol stack (e.g., RRC, SDAP, PDCP, RLC, MAC, and/orPHY) may be supported at a node. A base station (e.g., gNB 120A and/or120B) may comprise a base station central unit (CU) (e.g., gNB-CU 1420Aor 1420B) and at least one base station distributed unit (DU) (e.g.,gNB-DU 1430A, 1430B, 1430C, and/or 1430D), for example, if a functionalsplit is configured. Upper protocol layers of a base station may belocated in a base station CU, and lower layers of the base station maybe located in the base station DUs. An F1 interface (e.g., CU-DUinterface) connecting a base station CU and base station DUs may be anideal or non-ideal backhaul. Fl-C may provide a control plane connectionover an F1 interface, and F1-U may provide a user plane connection overthe F1 interface. An Xn interface may be configured between base stationCUs.

A base station CU may comprise an RRC function, an SDAP layer, and/or aPDCP layer. Base station DUs may comprise an RLC layer, a MAC layer,and/or a PHY layer. Various functional split options between a basestation CU and base station DUs may be possible, for example, bylocating different combinations of upper protocol layers (e.g., RANfunctions) in a base station CU and different combinations of lowerprotocol layers (e.g., RAN functions) in base station DUs. A functionalsplit may support flexibility to move protocol layers between a basestation CU and base station DUs, for example, depending on servicerequirements and/or network environments.

Functional split options may be configured per base station, per basestation CU, per base station DU, per wireless device, per bearer, perslice, and/or with other granularities. In a per base station CU split,a base station CU may have a fixed split option, and base station DUsmay be configured to match a split option of a base station CU. In a perbase station DU split, a base station DU may be configured with adifferent split option, and a base station CU may provide differentsplit options for different base station DUs. In a per wireless devicesplit, a base station (e.g., a base station CU and at least one basestation DUs) may provide different split options for different wirelessdevices. In a per bearer split, different split options may be utilizedfor different bearers. In a per slice splice, different split optionsmay be used for different slices.

FIG. 15 shows example RRC state transitions of a wireless device. Awireless device may be in at least one RRC state among an RRC connectedstate (e.g., RRC Connected 1530, RRC Connected, etc.), an RRC idle state(e.g., RRC Idle 1510, RRC Idle, etc.), and/or an RRC inactive state(e.g., RRC Inactive 1520, RRC Inactive, etc.). In an RRC connectedstate, a wireless device may have at least one RRC connection with atleast one base station (e.g., gNB and/or eNB), which may have a contextof the wireless device (e.g., UE context). A wireless device context(e.g., UE context) may comprise at least one of an access stratumcontext, one or more radio link configuration parameters, bearer (e.g.,data radio bearer (DRB), signaling radio bearer (SRB), logical channel,QoS flow, PDU session, and/or the like) configuration information,security information, PHY/MAC/RLC/PDCP/SDAP layer configurationinformation, and/or the like configuration information for a wirelessdevice. In an RRC idle state, a wireless device may not have an RRCconnection with a base station, and a context of the wireless device maynot be stored in a base station. In an RRC inactive state, a wirelessdevice may not have an RRC connection with a base station. A context ofa wireless device may be stored in a base station, which may comprise ananchor base station (e.g., a last serving base station).

A wireless device may transition an RRC state (e.g., UE RRC state)between an RRC idle state and an RRC connected state in both ways (e.g.,connection release 1540 or connection establishment 1550; and/orconnection reestablishment) and/or between an RRC inactive state and anRRC connected state in both ways (e.g., connection inactivation 1570 orconnection resume 1580). A wireless device may transition its RRC statefrom an RRC inactive state to an RRC idle state (e.g., connectionrelease 1560).

An anchor base station may be a base station that may keep a context ofa wireless device (e.g., UE context) at least at (e.g., during) a timeperiod that the wireless device stays in a RAN notification area (RNA)of an anchor base station, and/or at (e.g., during) a time period thatthe wireless device stays in an RRC inactive state. An anchor basestation may comprise a base station that a wireless device in an RRCinactive state was most recently connected to in a latest RRC connectedstate, and/or a base station in which a wireless device most recentlyperformed an RNA update procedure. An RNA may comprise one or more cellsoperated by one or more base stations. A base station may belong to oneor more RNAs. A cell may belong to one or more RNAs.

A wireless device may transition, in a base station, an RRC state (e.g.,UE RRC state) from an RRC connected state to an RRC inactive state. Thewireless device may receive RNA information from the base station. RNAinformation may comprise at least one of an RNA identifier, one or morecell identifiers of one or more cells of an RNA, a base stationidentifier, an IP address of the base station, an AS context identifierof the wireless device, a resume identifier, and/or the like.

An anchor base station may broadcast a message (e.g., RAN pagingmessage) to base stations of an RNA to reach to a wireless device in anRRC inactive state. The base stations receiving the message from theanchor base station may broadcast and/or multicast another message(e.g., paging message) to wireless devices in their coverage area, cellcoverage area, and/or beam coverage area associated with the RNA via anair interface.

A wireless device may perform an RNA update (RNAU) procedure, forexample, if the wireless device is in an RRC inactive state and movesinto a new RNA. The RNAU procedure may comprise a RA procedure by thewireless device and/or a context retrieve procedure (e.g., UE contextretrieve). A context retrieve procedure may comprise: receiving, by abase station from a wireless device, a RAP; and requesting and/orreceiving (e.g., fetching), by a base station, a context of the wirelessdevice (e.g., UE context) from an old anchor base station. Therequesting and/or receiving (e.g., fetching) may comprise: sending aretrieve context request message (e.g., UE context request message)comprising a resume identifier to the old anchor base station andreceiving a retrieve context response message comprising the context ofthe wireless device from the old anchor base station.

A wireless device in an RRC inactive state may select a cell to camp onbased on at least a measurement result for one or more cells, a cell inwhich a wireless device may monitor an RNA paging message, and/or a corenetwork paging message from a base station. A wireless device in an RRCinactive state may select a cell to perform a RA procedure to resume anRRC connection and/or to send (e.g., transmit) one or more packets to abase station (e.g., to a network). The wireless device may initiate a RAprocedure to perform an RNA update procedure, for example, if a cellselected belongs to a different RNA from an RNA for the wireless devicein an RRC inactive state. The wireless device may initiate a RAprocedure to send (e.g., transmit) one or more packets to a base stationof a cell that the wireless device selects, for example, if the wirelessdevice is in an RRC inactive state and has one or more packets (e.g., ina buffer) to send (e.g., transmit) to a network. A RA procedure may beperformed with two messages (e.g., 2-stage or 2-step random access)and/or four messages (e.g., 4-stage or 4-step random access) between thewireless device and the base station.

A base station receiving one or more uplink packets from a wirelessdevice in an RRC inactive state may request and/or receive (e.g., fetch)a context of a wireless device (e.g., UE context), for example, bysending (e.g., transmitting) a retrieve context request message for thewireless device to an anchor base station of the wireless device basedon at least one of an AS context identifier, an RNA identifier, a basestation identifier, a resume identifier, and/or a cell identifierreceived from the wireless device. A base station may send (e.g.,transmit) a path switch request for a wireless device to a core networkentity (e.g., AMF, MME, and/or the like), for example, after or inresponse to requesting and/or receiving (e.g., fetching) a context. Acore network entity may update a downlink tunnel endpoint identifier forone or more bearers established for the wireless device between a userplane core network entity (e.g., UPF, S-GW, and/or the like) and a RANnode (e.g., the base station), such as by changing a downlink tunnelendpoint identifier from an address of the anchor base station to anaddress of the base station).

A base station may communicate with a wireless device via a wirelessnetwork using one or more technologies, such as new radio technologies(e.g., NR, 5G, etc.). The one or more radio technologies may comprise atleast one of: multiple technologies related to physical layer; multipletechnologies related to medium access control layer; and/or multipletechnologies related to radio resource control layer. Enhancing the oneor more radio technologies may improve performance of a wirelessnetwork. System throughput, and/or data rate of transmission, may beincreased. Battery consumption of a wireless device may be reduced.Latency of data transmission between a base station and a wirelessdevice may be improved. Network coverage of a wireless network may beimproved. Transmission efficiency of a wireless network may be improved.

FIG. 16 shows an example of a two-step RA procedure. The procedure maycomprise an uplink (UL) transmission of a two-step Msg1 1620, forexample, based on a two-step RACH configuration 1610 from a basestation. The two-step Msg1 1620 may be referred to as message A (e.g.,Msg A). The transmission may comprise a RAP transmission 1630 and one ormore TBs for transmission 1640. The UL transmission may be followed by adownlink (DL) transmission of a two-step Msg2 1650 that may comprise aresponse (e.g., random access response (RAR)) corresponding to theuplink transmission. The two-step Msg2 1650 may be referred to as amessage B (e.g., Msg B). The response may comprise contention resolutioninformation.

A wireless device may receive (e.g., from a base station) one or moreRRC messages to configure one or more parameters of a two-step RACHconfiguration 1610. The one or more RRC messages may be broadcasted ormulticasted to one or more wireless devices. The one or more RRCmessages may be wireless device-specific messages (e.g., a dedicated RRCmessage sent (e.g., transmitted) to a wireless device indicating RRCINACTIVE 1520 or RRC CONNECTED 1530). The one or more RRC messages maycomprise parameters for sending (e.g., transmitting) a two-step Msg11620. The parameters may indicate one or more of following: PRACHresource allocation, preamble format, SSB information (e.g., totalnumber of SSBs, downlink resource allocation of SSB transmission,transmission power of SSB transmission, and/or other information),and/or uplink radio resources for one or more TB transmissions.

A base station may receive (e.g., from a wireless device via a cell), aRAP transmission for UL time alignment and/or one or more TBs (e.g.,delay-sensitive data, wireless device ID, security information, deviceinformation such as IMSI, and/or other information), for example, in theUL transmission of a two-step RA procedure. A base station may send(e.g., transmit) a two-step Msg2 1650 (e.g., an RAR), for example, inthe DL transmission of the two-step RA procedure. The two-step Msg2 1650(e.g., an RAR) may comprise at least one of following: a timing advancecommand indicating the TA value, a power control command, an UL grant(e.g., radio resource assignment, and/or MCS), a wireless device ID forcontention resolution, an RNTI (e.g., C-RNTI or TC-RNTI), and/or otherinformation. The two-step Msg2 1650 (e.g., an RAR) may comprise apreamble identifier corresponding to the preamble 1630, a positive ornegative acknowledgement of a reception of the one or more TBs 1640,and/or an indication of a successful decoding of the one or more TBs1640. A two-step RA procedure may reduce RA latency compared with afour-step RA procedure for example, by integrating a RAP transmission(such as a process to obtain a timing advance value) with one or more TBtransmissions.

A base station may receive (e.g., from a wireless device via a cell) anRAP in parallel with one or more TBs, for example, in the ULtransmission of a two-step RA procedure. The wireless device may acquireone or more configuration parameters for the UL transmission before thewireless device starts a two-step RA procedure (e.g., at step 1610 inFIG. 16 ). The one or more configuration parameters may indicate one ormore of following: PRACH resource allocation, preamble format, SSBinformation (e.g., a number of transmitting SSBs, downlink resourceallocation of SSB transmissions, transmission power of SSB transmission,and/or other information), uplink radio resources (e.g., in terms oftime, frequency, code/sequence/signature) for one or more TBtransmissions, and/or power control parameters of one or more TBtransmissions (e.g., cell and/or wireless device specific poweradjustments used for determining (e.g., calculating) received targetpower, inter-cell interference control parameter that may be used as ascaling factor of pathloss measurement, reference signal power todetermine (e.g., calculate for) pathloss measurement, and/or one or moremargins).

A wireless device may generate an RAP. A two-step RACH configuration maycomprise RAP generating parameters (e.g., a root sequence) that may beemployed by the wireless device to generate an RAP. The wireless devicemay use the RAP generating parameters to generate one or more candidatepreambles and may randomly select one of the candidate preambles as theRAP. The RAP generating parameters may be SSB-specific and/orcell-specific. RAP generating parameters for a first SSB may bedifferent from or the same as RAP generating parameters for a secondSSB. A base station may send (e.g., transmit) a control message (e.g.,RRC message for a handover, and/or a PDCCH order for a secondary celladdition) that comprises a preamble index indicating an RAP dedicated toa wireless device to initiate a two-step RA procedure. The one or morecandidate preambles may be organized into groups that may indicate anamount of data for transmission. The amount of data may indicate one ormore TBs that remain in the buffer. Each of the groups may be associatedwith a range of data size. A first group of the groups may comprise RAPsindicated for small data transmissions. A second group may comprise RAPsindicated for larger data transmissions. A wireless device may determinea group of RAPs by comparing one or more thresholds and an amount ofdata, for example, based on an RRC message comprising one or morethresholds (e.g., transmitted by a based station). The wireless devicemay be able to indicate a size of data the wireless device may have fortransmission, for example, by sending (e.g., transmitting) an RAP from aspecific group of RAPs.

In a two-step RA procedure, a wireless device may send (e.g., transmit)a RAP via a RACH resource indicated by a two-step RACH configuration.The wireless device may send (e.g., transmit) one or more TBs via an ULradio resource indicated by a two-step RACH configuration. Thetransmission of the RAP may be overlapped in time (e.g., partially orentirely) with the transmission of the one or more TBs. The two-stepRACH configuration may indicate a portion of overlapping of radioresources between the RAP and one or more TB transmissions. The two-stepRACH configuration may indicate one or more UL radio resourcesassociated with one or more RAPs (and/or RAP groups) and/or the RACHresource. A wireless device may determine at least one UL radio resourcein which the wireless device may send (e.g., transmit) one or more TBsas a part of a two-step RACH procedure, for example, based on aselection of an RAP, an RAP group, and/or an RACH resource The one ormore UL radio resources may be indicated based on a frame structure(such as shown in FIG. 6 ), and/or OFDM radio structure (such as shownin FIG. 8 ), The indication may be with respect to an SFN (e.g., SFN=0),slot number, and/or OFDM symbol number for a time domain radio resource,and/or with respect to a subcarrier number, a number of resourceelements, a number of resource blocks, RBG number, and/or frequencyindex for a frequency domain radio resource. The one or more UL radioresources may be indicated based on a time offset and/or a frequencyoffset with respect to one or more RACH resources of a selected RAP. TheUL transmissions may occur (e.g., in the same subframe orslot/mini-slot) in consecutive subframes (or slot/mini-slot), or in thesame burst.

A PRACH resource and one or more associated UL radio resources for atwo-step Msgl may be allocated with a time offset and/or frequencyoffset, for example, such as provided (e.g., configured, determined,indicated, etc.) by RRC messages (e.g., as a part of RACH config.)and/or predefined (e.g., as a mapping table).

FIG. 17A, FIG. 17B, and FIG. 17C show examples of radio resourceallocations of a random access resource (e.g., PRACH) 1702 and one ormore associated radio resources 1704. UL radio resources may be based ona time offset 1706, a frequency offset 1708, and a combination of a timeoffset 1706 and a frequency offset 1708, respectively. FIG. 17A, FIG.17B, and FIG. 17C comprise a PRACH resource 1702 and a UL radio resource1704 that are associated with a single SSB transmission. The PRACHresource 1702 and/or the UL radio resource 1704 may be associated with afirst SSB transmission of one or more SSB transmissions.

A base station may acquire a UL transmission timing, for example, bydetecting an RAP sent (e.g., transmitted) PRACH resource 1702 based onthe time offset 1706 and/or the frequency offset 1708. A base stationmay detect and/or decode one or more TBs sent (e.g., transmitted) viaone or more associated UL radio resources 1704, for example, based onthe UL transmission timing acquired from the RAP detection. A basestation may send (e.g., transmit) one or more SSBs. Each of the one ormore SSBs may have one or more associated PRACH resources 1702 and/or ULradio resources 1704 provided by (e.g., configured by, indicated by,etc.) a two-step RACH configuration. A wireless device may measure oneor more SSBs. The wireless device may select at least one SSB, forexample, based on measured received signal strength (and/or based onother selection rule). The wireless device may respectively send (e.g.,transmit) an RAP and/or one or more TBs: via PRACH resources 1702associated with the at least one SSB, and/or via UL radio resources 1704associated with the PRACH resources 1702 and/or UL radio resources 1704associated with the at least one SSB.

A base station may use the RAP transmission to adjust UL transmissiontime for a cell and/or to aid in channel estimation for one or more TBs.A portion of the UL transmission for one or more TBs in a two-step RACHprocedure may comprise one or more of: a wireless device ID, a C-RNTI, aservice request such as buffer state reporting (e.g., a buffer statusreport) (BSR), a user data packet, and/or other information. A wirelessdevice in an RRC CONNECTED state may use a C-RNTI as an identifier ofthe wireless device (e.g., a wireless device ID). A wireless device inan RRC INACTIVE state may use a C-RNTI (if available), a resume ID,and/or a short MAC-ID as an identifier of the wireless device. Awireless device in an RRC IDLE state may use a C-RNTI (if available), aresume ID, a short MACID, an IMSI (International Mobile SubscriberIdentifier), a T-IMSI (Temporary-IMSI), and/or a random number as anidentifier of the wireless device.

In a two-step RACH procedure, the UL transmission may comprise one ormore TBs that may be sent (e.g., transmitted) in one or more ways. Firstresource(s) allocated for one or more TBs may be multiplexed with secondresource(s) allocated for an RAP transmission in time and/or frequencydomains. One or more resources may be configured (e.g., by a basestation) to be reserved for the UL transmission that may be indicated toa wireless device before the UL transmission. A base station may send(e.g., transmit) in a two-step Msg2 1650 (e.g., an RAR) that maycomprise a contention resolution message and/or an acknowledgement (ACKor NACK) message of the one or more TBs, for example, based on one ormore TBs sent (e.g., transmitted) by a wireless device in a two-stepMsg1 1620 of a two-step RA procedure. A wireless device may send (e.g.,transmit) one or more second TBs after the reception of an RAR. Thewireless device may send (e.g., transmit) an indicator, such as bufferstate reporting, in a two-step Msg1 1620 of a two-step RA procedure. Theindicator may indicate to a base station an amount of data the wirelessdevice to send (e.g., transmit) and/or an amount of data remains in abuffer. The base station may determine a UL grant based on theindicator. The wireless device may receive (e.g., from a base station)the UL grant to via an RAR.

A wireless device may receive two separate responses in a two-step/RAprocedure: a first response for RAP transmission, and a second responsefor one or more TB transmission. A wireless device may monitor orcontinue to monitor a common search space to detect the first responsewith a random access RNTI generated based on time and frequency indicesof a PRACH resource in which the wireless device may send (e.g.,transmit) an RAP. A wireless device may monitor or continue to monitor acommon search space and/or a wireless device specific search space todetect the second response. The wireless device may employ a C-RNTI(e.g., if configured) and/or a random access RNTI generated based on oneor more time indices and/or one or more frequency indices of a PRACHresource in which the wireless device may send (e.g., transmit) an RAP,for example, to detect the second response. The wireless device-specificsearch space may be predefined and/or configured by an RRC message.

One or more events may trigger a two-step RA procedure. The one or moreevents may be one or more of: an initial access from RRC_IDLE, a RRCconnection re-establishment procedure, a handover, a DL or a UL dataarrival during RRC_CONNECTED if UL synchronization status isnon-synchronized, a transition from RRC Inactive, a beam failurerecovery procedure, and/or a request for other system information. APDCCH order, a wireless device (e.g., a MAC entity of a wirelessdevice), and/or a beam failure indication may initiate a RA procedure.

A two-step RA procedure may be initiated based on one or more case-basedprocedures, services, or radio conditions. One or more wireless devicesmay be configured (e.g., by a base station in the cell under itscoverage) to use a two-step RA procedure, for example, based on a cellidentified and/or indicated as small (e.g., there may be no need for aTA). A wireless device may acquire the configuration, via one or moreRRC messages (e.g., system information blocks, multicast and/or unicastRRC signaling), and/or via L1 control signaling (e.g., PDCCH order) usedto initiate a two-step RA procedure.

A wireless device (e.g., a stationary or near stationary wireless devicesuch as a sensor-type wireless device) may have a stored and/orpersisted TA value. A two-step RA procedure may be initiated based onthe stored and/or persisted TA value. A base station having macrocoverage may use broadcasting and/or dedicated signaling to configure atwo-step RA procedure with one or more wireless devices having storedand/or persisted TA values under the coverage.

A wireless device in an RRC connected state may perform a two-step RAprocedure. The two -step RA procedure may be initiated if a wirelessdevice performs a handover (e.g., network-initiated handover), and/or ifthe wireless device requires or requests a UL grant for a transmissionof delay-sensitive data and there are no physical-layer uplink controlchannel resources available to send (e.g., transmit) a schedulingrequest. A wireless device in an RRC INACTIVE state may perform atwo-step RA procedure, for example, for a small data transmission whileremaining in the RRC INACTIVE state or for resuming a connection. Awireless device may initiate a two-step RA procedure, for example, forinitial access such as establishing a radio link, re-establishment of aradio link, handover, establishment of UL synchronization, and/or ascheduling request if there is no UL grant.

The following description presents one or more examples of a RACHprocedure. The procedures and/or parameters described in the followingmay not be limited to a specific RA procedure. The procedures and/orparameters described in the following may be applied for a four-step RAprocedure and/or a two-step RA procedure. A RA procedure may refer to afour-step RA procedure and/or a two-step RA procedure in the followingdescription.

A wireless device may receive (e.g., from a base station) one or moremessages indicating RA parameters of a four-step RA procedure (such asshown in FIG. 12 ) and/or a two-step RA procedure (such as shown in FIG.16 ). The one or more messages may be a broadcast RRC message, awireless device specific RRC message, and/or a combination thereof. Theone or more messages may comprise a RA configuration (e.g., at least oneof: RACH-ConfigCommon, RACH-ConfigGeneric, and/or RACH-ConfigDedicated).A wireless device may receive, from a base station, a common and/or ageneric random access resource configuration (e.g., at leastRACH-ConfigCommon and/or RACH-ConfigGeneric), for example, based on acontention based (e.g., four-step and/or a two-step) RA procedure. Awireless device may receive, from a base station, a dedicated randomaccess resource configuration (e.g., at least RACH-ConfigDedicated), forexample, based on a contention free (four-step and/or a two-step) RAprocedure.

A base station may send (e.g., transmit), to a wireless device, one ormore messages indicating RA parameters. The one or more messages may bebroadcast via RRC message, via wireless device specific RRC message,and/or via a combination thereof. The one or more messages may compriseat least one of a common, generic, and/or dedicated random accessresource configuration (e.g., RACH-ConfigCommon, RACH-ConfigGeneric,and/or RACH-ConfigDedicated). A wireless device may receive, from a basestation, a common and/or a generic random access resource configuration(e.g., RACH-ConfigCommon and/or RACH-ConfigGeneric), for example, for acontention based RA procedure. A wireless device may receive, from abase station, at least a dedicated random access resource configuration(e.g., RACH-ConfigDedicated), for example, for a contention free RAprocedure.

FIGS. 18A, 18B, and 18C show, respectively, examples of an RAR, a MACsubheader with backoff indicator (BI), and a MAC subheader with a RAPID.A wireless device may receive from a base station at least one RAR as aresponse of Msg1 1220 (as shown in FIG. 12 ) or two-step Msg1 1620(shown in FIG. 16 ) using an RA procedure. An RAR may be in a form ofMAC PDU comprising one or more MAC subPDUs and/or (optionally) padding.FIG. 18A is an example of an RAR. A MAC subheader may be octet-aligned.Each MAC subPDU may comprise one or more of the following: a MACsubheader with BI only; a MAC subheader with RAPID only (e.g.,acknowledgment for SI request); a MAC subheader with RAPID and MAC RAR.FIG. 18B shows an example of a MAC subheader with BI. A MAC subheaderwith BI may comprise one or more header fields (e.g., E/T/R/R/BI) asshown in FIG. 18B and described below. A MAC subPDU with BI may beplaced at the beginning of the MAC PDU, if included. MAC subPDU(s) withRAPID only, and/or MAC subPDU(s) with RAPID and MAC RAR, may be placedanywhere after a MAC subPDU with BI and, before padding as shown in FIG.18A. A MAC subheader with RAPID may comprise one or more header fields(e.g., E/T/RAPID) as shown in FIG. 18C. Padding may be placed at the endof the MAC PDU, if present. Presence and length of padding may beimplicit, for example, based on TB size, and/or a size of MAC subPDU(s).

A field (e.g., an E field) in a MAC subheader may indicate an extensionfield that may be a flag indicating if the MAC subPDU (including the MACsubheader) is the last MAC subPDU or not in the MAC PDU. The E field maybe set to “1” to indicate at least one more MAC subPDU follows. The Efield may be set to “0” to indicate that the MAC subPDU including thisMAC subheader is a last MAC subPDU in the MAC PDU. A field (e.g., a Tfield) may be a flag indicating whether the MAC subheader contains aRAPID or a BI (e.g., one or more backoff values may predefined and BImay indicate one of backoff value). The T field may be set to “0” toindicate the presence of a field (e.g., a BI field) in the subheader.The T field may be set to “1” to indicate the presence of a RAPID fieldin the subheader. A field (e.g., an R field) may indicate a reserved bitthat may be set to “0.” A field (e.g., a BI field) may indicate anoverload condition in the cell. A size of the BI field may be 4 bits. Afield (e.g., a RAPID field) may be a RAPID field that may identifyand/or indicate the transmitted RAP. A MAC RAR may not be included inthe MAC subPDU, for example, based on the RAPID in the MAC subheader ofa MAC subPDU corresponding to one of the RAPs configured for an SIrequest.

There may be one or more MAC RAR formats. At least one MAC RAR formatmay be employed in a four-step or a two-step RA procedure.

FIG. 19 shows contention based and contention-free random accessprocedures with LBT. A successful contention based random accessprocedure may use Msg 1 1920, Msg 2 1930, Msg 3 1940, and contentionresolution 1950 to perform the RA procedure with the wireless device 110and base station 120. The wireless device may perform a first LBT,determine that the medium is clear, and send Msg 1 1920 to a basestation 120. The base station 120 may perform a second LBT, determinethat the medium is clear, and send Msg 2 1930 to the wireless device110. The wireless device 110 may perform a third LBT, determine themedium is clear, and send Msg 3 1940 to the base station 120. The basestation 120 may perform a fourth LBT, determine that the medium isclear, and sends contention resolution 1950 to the wireless device 110.

A successful contention-free based RA procedure may use Msg 1 1920 andMsg 2 1930 to perform the RA procedure with the wireless device 110 andthe base station 120. The wireless device 110 may perform a first LBT,determine that the medium is clear, and send Msg 1 1920 to the basestation 120. The base station 120 may perform a second LBT, determinethat the medium is clear, and send Msg 2 1930 to the wireless device110.

A failure of a RA may occur due to LBT, for example, in an unlicensedband. At least one LBT may be performed prior to DL and/or ULtransmission. Msg 1 1920, Msg 2 1930, Msg 3 1940, and/or contentionresolution 1950 may require at least one LBT before the transmission(e.g., at least 4 LBTs), for example, in a contention based randomaccess procedure. Msg 1 1920 and Msg2 1930 may require at least one LBTeach (e.g., at least 2 LBTs), for example, for a contention-free randomaccess procedure. A base station and/or a wireless device may not send(e.g., transmit) a message (e.g., Msg 1 1920, Msg 2 1930, Msg 3 1940,and/or contention resolution 1950) for a RA procedure, for example, ifthe LBT procedure has failed prior to sending the message (e.g., CCA inLBT determines that a channel in unlicensed band is busy (e.g., occupiedby another device)).

A failure of an LBT procedure may result in degrading a user experience(e.g., in terms of QoS, capacity (e.g., throughput), and/or coverage). Abase station and/or a wireless device may wait until the channel becomesidle. This waiting may result in a latency problem to make a radio linkconnection between a base station and a wireless device. A failure of anLBT during a RA procedure may lead a long delay for a wireless device toreceive an UL grant and/or TA value from a base station. This delay mayresult in a call drop and/or traffic congestion. A failure of an LBTprocedure in a RA procedure for an SCell addition may lead a cellcongestion (e.g., load imbalancing) on one or more existing cells (e.g.,if an SCell may not take over traffic from the one or more existingcells in time).

An efficiency of RA procedure operating in an unlicensed band maydegrade with LBT failure, which may cause a latency/delay, and/orperformance degradation. Selecting two or more SSBs and performing oneor more LBT procedures via one or more PRACH occasions associated withthe two or more SSBs may increase a success rate of LBT procedures. Awireless device may measure a plurality of downlink reference signals(e.g., SSBs or CSI-RSs, if CSI-RS is configured by RRC). The wirelessdevice may select two or more SSBs by comparing RSRPs of the pluralityof downlink reference signals and a threshold. The threshold maycomprise a RSRP threshold SSB parameter (e.g., rsrp-ThresholdSSB) if theplurality of downlink reference signals are SSBs. The threshold maycomprise a RSRP threshold CSI-RS parameter (e.g., rsrp-ThresholdCSI-RS)if the plurality of downlink reference signals are CSI-RSs. The wirelessdevice may select two or more downlink referencing signals (SSBs orCSI-RSs) having RSRPs that are higher than the threshold. The wirelessdevice may determine one or more PRACH occasions associated with theselected two or more downlink reference signals (e.g., SSBs), forexample, based on SSBs being configured with the wireless device. Thewireless device may determine the one or more PRACH transmissions basedon an association between PRACH occasions and SSBs that may be indicatedby one or more RRC parameters (e.g., ra-ssb-OccasionMaskIndex). Thewireless device may determine one or more PRACH occasions associatedwith the selected two or more downlink reference signals (e.g.,CSI-RSs), for example, based on CSI-RSs being configured with thewireless device. The wireless device may determine the one or more PRACHtransmissions based on an association between PRACH occasions andCSI-RSs that may be indicated by one or more RRC parameters (e.g.,ra-OccasionList).

FIG. 20 is an example diagram of a two-step RA procedure with LBT. Atwo-step RA procedure may employ LBT in an unlicensed band. A basestation and/or a wireless device may not send (e.g., transmit) a message(e.g., two-step Msg 1 2020, preamble 2030, one or more TBs 2040, and/ortwo-step Msg 2 2050) for a RA procedure if LBT is failed prior tosending (e.g., transmitting) the message (e.g., CCA in LBT determinesthat a channel in unlicensed band is busy, e.g., occupied by otherdevice). The transmissions of the preamble 2030 and for one or more TBs2040 may have a same LBT procedure and/or different LBT procedures.

Radio resources for transmissions of a preamble 2030 and one or more TBs2040 may be configured in a same channel (or a same subband or a sameBWP or a same UL carrier), where a wireless device performs an LBTprocedure for the transmissions (e.g., based on a regulation). An LBTresult on the same channel (or the same subband or the same BWP or thesame UL carrier) may be applied for transmissions of the preamble 2030and for one or more TBs 2040.

FIG. 21 is an example of radio resource allocation for a two-step RAprocedure. PRACH resource 2130 and UL radio resources 2140 may betime-multiplexed, for example, based on a frequency offset in FIG. 21being zero. PRACH 2130 resource and UL radio resources 2140 may befrequency-multiplexed, for example, based on a time offset in FIG. 21being zero. The frequency offset in FIG. 21 may be an absolute number interms of Hz, MHz, and/or GHz, and/or a relative number (e.g., one ofindex from a set of frequency indices that arepredefined/preconfigured). The time offset in FIG. 21 may be an absolutenumber in terms of micro-second, milli-second, and/or second and/or arelative number (e.g., in terms of subframe, slot, mini-slot, OFDMsymbol). PRACH resource 2130 for transmission of the preamble 2130 andUL radio resources for transmission of one or more TBs 2140 may besubject to one LBT procedure if f1 2110 and f2 2120 are configured inthe same channel (or a same subband or a same BWP or a same UL carrier).One LBT procedure before a PRACH resource 2130 may be performed by awireless device (e.g., based on a regulation of unlicensed band). Aquantity of LBT procedures may be determined based on a value of thetime offset. One LBT procedure before a PRACH resource 2130 may beperformed by a wireless device, for example, if the value of a timeoffset is equal to and/or less than a threshold (e.g., that may beconfigured and/or defined by a regulation). The one LBT procedure maydetermine idle and a wireless device may perform a transmission of thepreamble 2030 via PRACH resource 2130 followed by a second transmissionof one or more TBs 2040 via the UL radio resources 2140 with no LBTprocedure (the transmission order may be switched if the UL radioresources 2140 is allocated before PRACH resource 2130 in time domain).PRACH and UL radio resources may be allocated closely enough in timedomain. A wireless device may perform a first LBT procedure before aPRACH resource 2130 and perform a second LBT procedure before Ul radioresources 2140, for example, based on the value of time offset beinglarger than the threshold

A bandwidth of BWP and/or UL carrier may be larger than a first value(e.g., 20 MHz). f1 2110 and f2 2120 may be configured in the bandwidth.A wireless device may perform an LBT procedure and apply a result (e.g.,idle or busy) of the LBT procedure to the transmission of the preamble2030 and UL radio resources for transmission of one or more TBs 2040. Awireless device may perform the transmissions of the preamble 2030 andfor one or more TBs 2040. If the channel is busy, a wireless device maynot perform the transmissions of the preamble 2030 and for one or moreTBs 2040, for example, based on the channel being idle.

A bandwidth of BWP and/or UL carrier may be less than a first value(e.g., 20 MHz). f1 2110 and f2 2120 may be configured in the bandwidth.A wireless device may perform an LBT procedure and apply a result (e.g.,idle or busy) of the LBT procedure to the transmission of the preamble2030 and UL radio resources for transmission of one or more TBs 2040. Awireless device may perform a first transmission of the preamble 2030followed by a second transmission of one or more TBs 2040, for example,based on if the channel being idle. A wireless device may not performthe transmissions of the preamble 2030 and for one or more TBs 2040, forexample, based on the channel being busy.

Radio resources for transmissions of the preamble 2030 and one or moreTBs 2040 may be configured in different channels, different subbands,different BWPs, and/or different UL carriers (e.g., one in NUL and theother one in SUL) that may require separate LBT procedures. A wirelessdevice may perform a LBT procedure per one or more channels, per one ormore subbands, per one or more BWPs, and/or per one or more UL carriers.

FIG. 22 shows an example of one or more LBT procedures performed for atwo-step RA procedure UL radio resources 2250 may be allocated before oraligned with PRACH resources 2230 in time. A wireless device may performa first LBT procedure (e.g., LBT 2240 in FIG. 22 ) before a firsttransmission of preamble 2030 (e.g., via PRACH resources 2230) andperform a second LBT procedure (e.g., LBT 2260 in FIG. 22 ) before asecond transmission of one or more TBs 2040 (e.g., via UL radioresources 2250). A wireless device may perform none of, one of, or bothof the first transmission and the second transmission, depending onresults of the first LBT procedure and second LBT procedure. SeparateLBTs before a PRACH message and/or data may provide benefits, such as:earlier transmission of the first transmission and/or secondtransmission by a wireless device, earlier transmission of a preamblethan if a larger LBT were used, and increased probability that atransmission will be successful.

The first transmission may be performed if a first result of the firstLBT procedure is idle. The second transmission may be independent of thefirst result. The second transmission may be performed if a secondresult of the second LBT procedure is idle. A wireless device may send(e.g., transmit) the preamble 2030, for example, in response to thefirst LBT procedure being idle. The wireless device may not be able tosend (e.g., transmit) one or more TBs 2040 in response to the second LBTprocedure being busy. A wireless device may not send (e.g., transmit)the preamble 2030 in response to the first LBT procedure being busy. Thewireless device may send (e.g., transmit) one or more TBs 2040 inresponse to the second LBT procedure being idle. In a two-step RAprocedure, one or more TBs may comprise an identifier of the wirelessdevice, for example, so that a base station may identify and/or indicatewhich wireless device sent (e.g., transmitted) the one or more TBs. Theidentity may be configured by the base station and/or may be at least aportion of wireless device-specific information (e.g., resume ID, DMRSsequence/index, IMSI, etc.). A base station may identify and/or indicatethe wireless device based on the identity in the one or more TBs, forexample, based on a wireless device sending (e.g., transmitting) one ormore TBs with no preamble 2030 (e.g., if a channel, e.g. PRACH 2230 isbusy).

Separate LBT procedures for transmissions of a preamble and one or moreTBs may be performed, for example, based on a two-step RA procedureconfigured in an unlicensed band. A wireless device may be configured(e.g., by a base station) with separate LBT procedures for a widebandoperation (e.g., based on a bandwidth greater than 20 MHz). A wirelessdevice may be configured (e.g., by a base station) with a widebandcomprising one or more subbands and/or one or more BWPs, for example,based on wideband operation. Some of the one or more subbands mayoverlap in the frequency domain. Some of the one or more subbands maynot overlap in the frequency domain. Some of the one or more BWPsoverlap in the frequency domain. Some of the one or more BWPs may notoverlap in the frequency domain. Separate LBT procedures may be used fortransmissions via the two radio resources, for example, based on awideband operation and/or two radio resources being allocated with aspace larger than a threshold (e.g., 20 MHz). A wideband may compriseone or more subbands, and two radio resources may be allocated indifferent subbands. A first transmission scheduled in a first subbandmay use a first LBT procedure, and a second transmission scheduled in asecond subband may use a second LBT procedure. The first LBT procedureand the second LBT procedure may be independent of each other.

UL radio resources for transmission of one or more TBs 2040 may besubject to a first LBT procedure (e.g., LBT 2260) and be independent ofa second LBT procedure (e.g., LBT 2240) for transmission of the preamble2030. PRACH resources 2230 for transmission of the preamble 2030 may besubject to a second LBT procedure (e.g., LBT 2260) and be independent ofa first LBT procedure (e.g., LBT 2260) for transmission of one or moreTBs 2040. A wireless device may perform separate LBT procedures for afirst transmissions of the preamble 2030 and a second transmission ofone or more TBs 2040, for example, based on f1 2210 and f2 2220 beingconfigured in different channels, different subbands, different BWPs,and/or different UL carriers.

FIGS. 23A and 23B are examples of one or more LBT procedures performedfor a two-step RA procedure in an unlicensed band. The resourceallocation and the separate LBT procedures in FIG. 22 may be resultedfrom FIGS. 23A and/or 23B. A wireless device may be configured (e.g., bya base station) with one or more PRACH resources and one or more ULradio resources in different channels (BWPs and/or UL carriers). Thewireless device may one or more first opportunities to send (e.g.,transmit) preambles and one or more second opportunities to send (e.g.,transmit) one or more TBs. A wireless device may have two opportunitiesvia random access resources (e.g., PRACH resource 2330 and PRACHresource 2430) for preamble transmission, for example, as shown in FIG.23A. A wireless device may select one of two opportunities, for example,based on LBT results. A wireless device may perform a first LBTprocedure (e.g., LBT 2340) and a second LBT procedure (e.g., LBT 2440 asshown in FIG. 23A). A wireless device may select one of PRACH resourcesassociated either a first LBT procedure or a second LBT procedure (e.g.,based on random selection), for example, based on the results of thefirst and second LBT procedures being idle. A wireless device may selecta PRACH resource associated with the LBT result being idle for preambletransmission, for example, based on one of LBT result being idle and theother of LBT result being busy. A wireless device may not send (e.g.,transmit) a preamble and may perform one or more LBT procedures for oneor more TB transmissions, for example, based on the first and second LBTprocedure results being busy.

A wireless device may have one or more opportunities for transmission ofone or more TBs via UL radio resources (e.g., in a similar way that awireless device has for preamble transmission above). The one or moreopportunities for transmission of one or more TBs may be independent ofone or more opportunities for transmission of preamble. The wirelessdevice may perform one or more LBT procedures to gain access to achannel to send (e.g., transmit) one or more TBs, for example, based ona wireless device not sending (e.g., transmitting) a preamble due to aresult (e.g., busy) of LBT procedure. A wireless device may perform afirst LBT procedure (e.g., LBT 2320) followed by a first transmissionopportunity of one or more TBs via first UL radio resources 2310 and asecond LBT procedure (e.g., LBT 2460 in FIG. 23A) followed by a secondtransmission opportunity of one or more TBs via second UL radioresources 2450, as shown in FIG. 23A. A wireless device may select oneof the opportunities, for example, depending on LBT results. A wirelessdevice may send (e.g., transmit) one or more TBs via UL radio resources2450, for example, based on LBT 2320 being busy and/or LTB 2460 beingidle as shown in FIG. 23A. A wireless device may not send (e.g.,transmit) any preamble, for example, based on one or more LBT procedures(e.g., LBT 2440 and LBT 2340 in FIG. 23A) to gain access for sending(e.g., transmitting) a preamble result in busy. A wireless device mayperform one or more second LBT procedures (e.g., LBT 2320 and LBT 2460in FIG. 23A) for transmission of one or more TBs.

The wireless device may receive, from a base station, one or morecontrol message (e.g., RRC messages and/or PDCCH messages) indicatingone or more associations between PRACH resources and UL radio resources,for example, before a wireless device initiates a two-step RA procedure.The associations may be one-to-one, multi-to-one, one-to-multi, and/ormulti-to-multi between one or more PRACHs resources and one or more ULradio resources. A wireless device may determine which UL radioresources and/or which PRACH resources to select, for example, based onthe associations. The associations may indicate one-to-multi associationfrom PRACH resource 2430 to UL radio resources 2450 and UL radioresources 2310, for example, as shown in FIG. 23A. The associations mayindicate one-to-one association from PRACH resources 2330 to UL radioresources 2450. A wireless device may perform one or more LBT procedures(depending on a regulation and/or resource allocation whether theresources are in the same channel) for transmission of one or more TBsdepending on a selection of PRACH resources. A wireless device mayperform two LBT procedures (LBT 2440 and LBT 2340), for example, asshown in FIG. 23A. A wireless device may send (e.g., transmit) apreamble via PRACH resources 2430, for example, based on LBT 2440 beingidle but LBT 2340 being busy. The wireless device may determine (e.g.,select) one or more candidate UL radio resources based on a configuredassociation of PRACH resources 2430, which may be one-to-multi fromPRACH resources 2430 to UL radio resources 2450 and UL radio resources2310. The wireless device may perform LBT 2320 and LBT 2460 based on theconfigured association. A wireless device may send (e.g., transmit) oneor more TBs, depending on the results of the LBT procedures. FIG. 23B isan example of a two-step RA procedure. UL radio resources are associatedwith one PRACH resource. An association may be configured (e.g., by abase station) from PRACH resource 2430 to UL radio resource 2450 and ULradio resources 2350.

The PRACH resource and/or UL radio resources in FIGS. 21, 22, 23A,and/or 23B may be associated with at least one reference signalconfiguration (e.g., SSB, CSI-RS, DM-RS). A wireless device may receive(e.g., from a base station) at least one control message to indicatesuch an association. A configuration of each reference signal may havean association with at least one PRACH resource, that may be configuredby RRC message and/or PDCCH signals, for example, based on the basestation sending (e.g., transmitting) a plurality of reference signals.In one or more downlink channels, there may be a plurality of PRACHresources and a plurality of UL radio resources associated with theplurality of PRACH resources.

A failure of a LBT procedure may result in degrading a user experience(e.g., in terms of QoS, capacity (throughput), and/or coverage). A basestation and/or a wireless device may wait until the channel becomesidle. This wait may result in a latency problem to make a radio linkconnection between a base station and a wireless device. A failure of anLBT procedure during a RA procedure may lead a long delay for a wirelessdevice to receive an UL grant and/or TA value from a base station. Thisfailure may result in a call drop and/or traffic congestion. A failureof an LBT in a RA procedure for an SCell addition may lead to cellcongestion (e.g., load imbalancing) on one or more existing cells, forexample, because an SCell may not take over traffic from the one or moreexisting cells in time.

A wireless device may detect/attempt to detect DCI (e.g., DCI format1_0) during a window (e.g., ra-responseWindow), for example, based on orin response to a transmission received via a channel (e.g., accesschannel, PRACH, etc.). The DCI may be CRC scrambled by a correspondingRA-RNTI. The wireless device may determine a first (e.g., earliest)CORESET, for example, based on at least one symbol after the last symbolof the PRACH. The wireless device may receive a PDCCH for Type1-PDCCHCSS set in the first (e.g., earliest) CORESET. The wireless device maystart the window at a first symbol of the first (e.g., earliest)CORESET, for example, based on or in response to determining the first(e.g., earliest) CORESET. The wireless device may determine a symbolduration for determining the first (e.g., earliest) CORESET, forexample, based on a SCS for the Type1-PDCCH CSS set.

The base station may provide (e.g., send/transmit) the wireless devicewith a length of the window by a higher layer parameter (e.g.,ra-ResponseWindow). The length of the window may be in quantity/numberof slots. The wireless device may determine a slot duration for thelength of the window, for example, based on the SCS for the Type1-PDCCHCSS set.

The wireless device may detect the DCI (e.g., DCI format 1_0) within thewindow. The DCI may be CRC scrambled by the corresponding RA-RNTI. Thewireless device may detect a transport block in a PDSCH within thewindow. The DCI may schedule the transport block in the PDSCH., based onor in response to detecting the transport block. A lower layer (e.g.,PHY, MAC) of the wireless device may pass the transport block to ahigher layer of the wireless device (e.g., MAC, RRC). The wirelessdevice (e.g., the higher layer of the wireless device) may parse thetransport block for a random access preamble identity (RAPID) associatedwith the PRACH transmission. The wireless device (e.g., the higher layerof the wireless device) may determine and/or identify the RAPID in atleast one random access response (RAR) message of the transport block.The higher layer may indicate an uplink grant (e.g., RAR uplink grant)to the lower layer of the wireless device, for example, based on or inresponse to the determining/identifying. The higher layer of thewireless device may indicate to the lower layer (e.g., physical layer)of the wireless device to transmit a second PRACH, for example, based onor in response to not detecting the DCI (e.g., DCI format 1_0) withinthe window. The higher layer of the wireless device may indicate to thelower layer (e.g., physical layer) of the wireless device to transmit asecond PRACH, for example, based on or in response to not correctlyreceiving the transport block in the PDSCH within the window. The higherlayer of the wireless device may indicate to the lower layer (e.g.,physical layer) of the wireless device to transmit a second PRACH, forexample, based on or in response to not identifying the RAPID associatedwith the PRACH transmission from the wireless device.

The wireless device may send (e.g., transmit) the second PRACH within afirst offset (e.g., 1 msec or any time duration), for example based onor in response to the higher layer indicating to the lower layer of thewireless device to send (e.g., transmit) the second PRACH. The firstoffset may be after the last symbol of the window. The wireless devicemay send (e.g., transmit) the second PRACH within the first offset afterthe last symbol of the PDSCH, for example, based on or in response tothe higher layer indicating to the lower layer to send (e.g., transmit)the second PRACH. The first offset may be based on the wireless device'scapability for a PDSCH reception. The wireless device may detect theDCI. The DCI may be CRC scrambled by the corresponding RA-RNTI. Thewireless device may detect (e.g., receive) the transport block in thePDSCH.

The wireless device may initiate a PRACH transmission, for example,based on or in response to receiving a PDCCH order from the basestation. The RAR UL grant may schedule a PUSCH transmission (e.g., Msg3)from the wireless device. The RAR UL grant may comprise at least one of:a frequency hopping flag (e.g., 1 bit), a frequency resource allocationfor the PUSCH transmission (e.g., 14 bit), a time resource allocationfor the PUSCH transmission (e.g., 4 bit), MCS (e.g., 4 bit), a TPCcommand for the PUSCH transmission (e.g., 3 bit), and/or a CSI request(e.g., 1 bit). The wireless device may determine the MCS of the PUSCHtransmission, for example, based on the MCS in the RAR UL grant. The RARUL grant in the at least one RAR message may schedule a PUSCHtransmission (e.g., Msg3). The wireless device may transmit a secondtransport block in the PUSCH using a first redundancy version (e.g., 0).

The base station may reschedule a sending/resending (e.g.,transmission/retransmission) of the second transport block with a secondDCI (e.g., DCI format 0_0). The second DCI may be CRC scrambled by aTC-RNTI. The TC-RNTI may be provided in the at least one RAR message.The wireless device may send (e.g., transmit) the PUSCH, scheduled bythe RAR UL grant, without repetitions.

The wireless device may receive the PDSCH with the at least one RARmessage for the PRACH transmission. The at least one RAR message may endin a first slot (e.g., slot n). The wireless device may send (e.g.,transmit) the PUSCH in a second slot, for example, based on or inresponse to the at least one RAR message ending in a first slot. Thesecond slot may be based on the first slot. The second slot may be equalto the first slot plus an offset. The offset may be based on a wirelessdevice's capability, PDSCH processing time, and/or PUSCH preparationtime.

The base station may not provide the wireless device with a C-RNTI. Thewireless device may be in an RRC-IDLE mode. The wireless device may bein RRC-INACTIVE mode. The wireless device may detect/attempt to detect athird DCI (e.g., DCI format 1_0), for example, based on or in responseto not being provided with the C-RNTI (e.g., if the wireless devicetransmits the PUSCH scheduled by the RAR UL grant). The third DCI may beCRC scrambled by the TC-RNTI. The third DCI may schedule a second PDSCHthat may comprise a wireless device contention resolution identity.

A wireless device may receive one or more configuration parameters froma base station. The one or more configuration parameters may be for atwo-step random access (RA) procedure of a cell (e.g., PCell, SCell).For example, the one or more configuration parameters may indicate atleast one of following: one or more RACH occasions (e.g., time-frequencyresources), one or more random access preambles (RAPs) (or RAP groups),preamble format, SSB information (e.g., a number of transmitting SSBs,downlink resource allocation of SSB transmissions, transmission power ofSSB transmission, and/or other information), one or more uplink radioresources (in terms of time, frequency, code/sequence/signature), and/orpower control parameters (e.g., cell and/or wireless device specificpower adjustments used for calculating received target power, inter-cellinterference control parameter that may be used as a scaling factor ofpathloss measurement, reference signal power to calculate for pathlossmeasurement, and/or one or more margins).

The two-step RA procedure may comprise a first uplink (UL) transmissionof a RAP (e.g., two-step Msgl) of the one or more RAPs and/or a secondUL transmission of one or more transport blocks (e.g., FDM-ed, TDM-ed).The base station may send (e.g., transmit) a two-step Msg2 to thewireless device, for example, based on or in response to receiving theRAP and/or the one or more transport blocks. The two-step Msg2 maycomprise a response, such as a random access response (RAR). The RAR maycorrespond to the first UL transmission and/or the second ULtransmission. The two-step Msg2 may comprise at least one of following:a timing advance command indicating the TA value, a power controlcommand, an RAR UL grant (e.g., radio resource assignment, and/or MCS),a wireless device ID for contention resolution (e.g., a contentionresolution message), an RNTI (e.g., C-RNTI or TC-RNTI), and/or otherinformation. The two-step Msg2 (e.g., an RAR) may comprise a preambleidentifier corresponding to the RAP, a positive (ACK) or negativeacknowledgement (NACK) of a reception of the one or more transportblocks, and/or an indication of a successful decoding of the one or moretransport blocks. The wireless device may send (e.g., transmit) one ormore second transport blocks, for example, based on or in response tothe two-step Msg2.

The wireless device may send (e.g., transmit) the RAP via at least oneRACH resource of the one or more RACH occasions indicated by the one ormore configuration parameters in the two-step random access procedure.The wireless device may send (e.g., transmit) the one or more transportblocks via at least one UL radio resource of the one or more uplinkradio resources indicated by the one or more configuration parameters.The one or more configuration parameters may indicate one or moreassociations between the one or more uplink radio resources and/or theone or more RAPs (or RAP groups). The one or more configurationparameters may indicate one or more associations between the one or moreuplink radio resources and/or the one or more RACH occasions. The one ormore associations may be one-to-one, many-to-one, one-to-many, and/ormany-to-many between one or more RAPs and/or one or more uplink radioresources. The one or more associations may be one-to-one, many-to-one,one-to-many, and/or many-to-many between one or more RACH occasionsand/or one or more uplink radio resources.

A wireless device may determine which UL radio resource and/or whichPRACH resource or RAP should/needs to be selected, for example, based onthe associations. The wireless device may determine at least one ULradio resource of the one or more uplink radio resources, for example,based on the selection of the RAP and the one or more associations(e.g., if the wireless device selects a two-step RA procedure). Thewireless device may send (e.g., transmit) the one or more transportblocks via the at least one UL radio resource for RA procedure (e.g.,the two-step RA procedure), for example, based on or in response todetermining at least one UL radio resource of the one or more uplinkradio resources.

The first transmission of the RAP may overlap in time and/or infrequency (e.g., partially or entirely) with the second transmission ofthe one or more transport blocks. The first transmission of the RAP maybe multiplexed with the second transmission of the one or more transportblocks in the time and/or frequency domain.

A wireless device may perform a listen-before-talk (LBT) procedure on anuplink channel. The wireless device may perform an uplink transmissionvia the uplink channel, for example, based on or in response to asuccess of the LBT procedure. The success of the LBT procedure maycomprise the wireless device determining that the uplink channel isidle/unoccupied (e.g., not being occupied by another wireless device).The wireless device may not perform an uplink transmission (e.g.,two-step Msg 1, preamble, one or more transport blocks) via the uplinkchannel, for example, based on or in response to a failure of the LBTprocedure. Failure of the LBT procedure may comprise the wireless devicedetermining that the uplink channel (e.g., PRACH, PUSCH, PUCCH) for theuplink transmission is busy/occupied (e.g., occupied by another wirelessdevice).

The wireless device may perform a first LBT procedure for the first ULtransmission of the RAP and/or a second LBT procedure for the second ULtransmission. The first LBT procedure and/or the second LBT proceduremay be the same (e.g., simultaneous, same frequency, same time, etc.).Alternatively, the first LBT procedure and/or the second LBT proceduremay be different (e.g., different times, frequency, etc.). The wirelessdevice may determine a success of the first LBT procedure for the RAP.The wireless device may perform the first UL transmission of the RAP viathe RACH resource, for example, based on or in response to the successof the first LBT procedure. The wireless device may not perform thesecond LBT procedure for the second UL transmission of the one or moretransport blocks, for example, based on or in response to the success ofthe first LBT procedure. The wireless device may perform the second ULtransmission via the at least one UL radio resource if the first LBTprocedure is successful, for example, based on or in response to the notperforming the second LBT. The PRACH and/or UL radio resources may beallocated close in the time domain. The wireless device may perform thefirst and the second UL transmissions back-to-back, for example, basedon or in response to the PRACH and/or UL radio resources being allocatedclose in time.

The wireless device may determine a success of the first LBT procedure(e.g., idle/unoccupied) for the RAP. The wireless device may perform thefirst UL transmission of the RAP via the RACH resource, for example,based on or in response to the success of the first LBT procedure. Thewireless device may perform the second UL transmission of the one ormore transport blocks via the at least one UL radio resource, forexample, based on or in response to the success of the first LBTprocedure.

The wireless device may determine a failure of the first LBT procedure(e.g., busy/occupied) for the RAP. The wireless device may not performthe first UL transmission of the RAP via the RACH resource, for example,based on or in response to the failure of the first LBT procedure. Thewireless device may not perform the second UL transmission of the one ormore transport blocks via the at least one UL radio resource, forexample, based on or in response to the failure of the first LBTprocedure.

A wireless device may receive one or more messages (e.g., RRC connectionreconfiguration message, RRC connection reestablishment message, and/orRRC connection setup message) from a base station. The one or moremessages may comprise one or more configuration parameters for a cell(e.g., PCell, PSCell, SCell). The one or more configuration parametersmay comprise bandwidth part (BWP) configuration parameters for aplurality of downlink BWPs of the cell and/or a plurality of uplink BWPsof the cell, and/or any other resource configurations for a plurality ofresources of the cell.

The wireless device may operate in a paired spectrum (e.g., frequencydivision duplex (FDD)). The one or more configuration parameters maycomprise downlink BWP specific indices for the plurality of downlinkBWPs and/or uplink BWP specific indices for the plurality of uplinkBWPs. Each downlink BWP may be indicated/identified by a respectivedownlink BWP specific index (e.g., provided by a higher layer parameterBWP-ID). Each uplink BWP may be indicated/identified by a respectiveuplink BWP specific index (e.g., provided by a higher layer parameterBWP-ID).

At a time slot, the wireless device may operate on a first downlink BWPand/or a second uplink BWP. The wireless device may be active on thefirst downlink BWP and/or the second uplink BWP at the time slot, forexample, based on or in response to the operating on the first downlinkBWP and/or he second uplink BWP. The first downlink BWP and the seconduplink BWP may be an active downlink BWP and an active uplink BWP of thecell, respectively (e.g., during the time slot).

The wireless device may initiate a random access procedure (e.g.,contention-based random access procedure, contention-free random accessprocedure), for example, if the first downlink BWP is the activedownlink BWP and/or the second uplink BWP is the active uplink BWP ofthe cell (e.g., during the time slot). The wireless device may performthe random access procedure on the first downlink BWP and/or the seconduplink BWP. The random access procedure may be started (e.g., initiated)for an initial access from RRC_IDLE, an RRC Connection Re-establishmentprocedure, a handover, a DL or UL data arrival during RRC_CONNECTED ifUL synchronization status is non-synchronized, a transition fromRRC_INACTIVE, a time alignment establishment at an SCell addition, abeam failure recovery, and/or a request for other system information(SI).

The one or more configuration parameters may comprise one or more PRACHresources on the second uplink BWP. The one or more configurationparameters may comprise one or more RSs (e.g., SS/PBCH blocks, CSI-RS).The one or more configuration parameters may comprise one or moreassociations (or correspondence) between the one or more RSs and the oneor more PRACH resources (e.g., the association may be one-to-one,one-to-many, many-to-one, etc.). The association may be provided byconfiguration parameters (e.g., RACH-ConfigDedicated,CandidateBeamRSList, RACH-ConfigCommon, ra-ssb-OccasionMaskIndex,ra-OccasionList etc.).

Performing the random access procedure on the second uplink BWP maycomprise performing a random access resource selection. Performing therandom access resource selection may comprise selecting a first RS froma plurality of RSs. The first RS may be a first SS/PBCH block and/or afirst CSI-RS. The first RS may be associated with (or correspond to) aPRACH resource of a plurality PRACH resources configured on the seconduplink BWP. The PRACH resource may comprise at least one preamble (e.g.,associated with PREAMBLE_INDEX) and/or at least one PRACH occasion(e.g., time, frequency, code) on the second uplink BWP.

The wireless device may perform a random access preamble transmissionfor example, based on or in response to performing the random accessresource selection. The wireless device may send (e.g., transmit), in afirst slot, the at least one preamble via the at least one PRACHresource of the second uplink BWP for the random access procedure. Thewireless device may start, from a second slot, a configured responsewindow (e.g., ra-responseWindow), for example, based on or in responseto transmitting the at least one preamble in the first slot. Theconfigured response window may be configured by the one or moreconfiguration parameters (e.g., RACH-ConfigCommon,BeamFailureRecoveryConfig). The wireless device may monitor (e.g.,listen) for a random access response (RAR) corresponding to the at leastone preamble, for example, if the configured response window is running.Monitoring for the random access response may comprise monitoring atleast one PDCCH in the second downlink BWP of the cell (e.g., SpCell)for DCI (e.g., a downlink assignment, an uplink grant, etc.). The DCImay be CRC scrambled by a C-RNTI or MCS-C-RNTI of the wireless device.The random access procedure may be initiated for a beam failure recoveryof the cell. The DCI may be indicated/identified using a CRC scrambledby an RA-RNTI. An offset between the first slot and the second slot maybe fixed (e.g., 1 slot, 2 slots, 3 slots, 4 slots, etc.) or variable.The second slot may be at a first PDCCH occasion of the second downlinkBWP from the conclusion (e.g., end) of transmitting the at least onepreamble.

The random access procedure (e.g., contention-free random accessprocedure) for the beam failure recovery may be successfully completed,for example, based on or in response to receiving the DCI (e.g.,scrambled by a C-RNTI or an MCS-C-RNTI) on the at least one PDCCH in thesecond downlink BWP of the cell within the configured response window.The random access response may comprise a first MAC subPDU with a randomaccess preamble identifier. The random access preamble identifier may beassociated with (e.g., correspond to) the at least one preamble (e.g.,PREAMBLE_INDEX).

A reception of the random access response may be successfully completed,for example, if the random access procedure is not initiated for a beamfailure recovery (e.g., contention-free random access procedure for thebeam failure recovery). A reception of the random access response may besuccessfully completed, for example, based on or in response toreceiving the DCI (e.g., scrambled by RA-RNTI) in the at least one PDCCHof the second downlink BWP within the configured response window and/orthe random access preamble identifier being associated with (e.g.,correspond to) the at least one preamble.

The random access procedure (e.g., contention-free random accessprocedure) may be successfully completed, for example, if the randomaccess procedure is not initiated for a beam failure recovery and/or areception of the random access response is successfully completed. Therandom access procedure (e.g., contention-free random access procedure)may be successfully completed, for example, based on or in response toreceiving the DCI (e.g., scrambled by an RA-RNTI) on the at least onePDCCH in the second downlink BWP of the cell within the configuredresponse window.

The configured response window may expire. The wireless device may notreceive the

DCI within the configured response window. The wireless device maydetermine (e.g., consider) a reception of the random access responseunsuccessful, for example, based on or in response to the configuredresponse window expiring and/or the wireless device not receiving theDCI (e.g., scrambled by a C-RNTI). The wireless device may determine(e.g., consider) a reception of the random access response to beunsuccessful, for example, based on or in response to the configuredresponse window expiring and/or a random access response comprising therandom access preamble identifier being associated with (e.g.,correspond to) the at least one preamble. The wireless device mayincrement a preamble transmission counter variable (e.g.,PREAMBLE_TRANSMISSION_COUNTER) by one, for example, based on adetermination that reception of the random access response unsuccessful.The preamble transmission counter variable may be equal to or greaterthan a preamble maximum transmission parameter (e.g., RRC parameterpreambleTransMax), for example, based on or in response to incrementingthe preamble transmission counter variable.

The cell may be an SpCell (e.g., PCell, PSCell). The wireless device maysend (e.g., transmit) the at least one preamble on the SpCell, forexample, based on or in response to the cell being the SpCell. Thewireless device may indicate/identify a problem of the random accessprocedure to one or more upper layers (e.g., RRC), for example, based onor in response to the preamble transmission counter variable being equalto or greater than the preamble maximum transmission parameter.

The cell may be an SCell. The wireless device may send (e.g., transmit)the at least one preamble on the SCell, for example, based on or inresponse to the cell being the SCell. The wireless device may completethe random access procedure unsuccessfully, for example, based on or inresponse to the preamble transmission counter variable being equal to orgreater than the preamble maximum transmission parameter. The upperlayers may trigger a radio link failure that may lead to prolongedrandom access delay and/or degraded user experience, for example, basedon or in response to indicating the problem of the random accessprocedure to the one or more upper layers (e.g., RRC).

The preamble transmission counter variable may be less than the preamblemaximum transmission parameter plus one (or any othervalue/quantity/number), for example, based on or in response toincrementing the preamble transmission counter variable. The wirelessdevice may determine/consider the random access procedure to beincomplete, for example, based on or in response to the preambletransmission counter variable being less than the preamble maximumtransmission parameter plus one (or any other value/quantity/number).The wireless device may select a random back-off time, for example,based on or in response to the determining/considering the random accessprocedure to be incomplete. The random back-off time may be selectedaccording to a uniform distribution between zero and a preamble back-offvariable in the RAR. The wireless device may start a back-off timer witha value indicated by the random back-off time, for example, based on orin response to selecting the random back-off time.

The wireless device may perform a second random access resourceselection, for example, at a time that the back-off timer is running.The wireless device may select a second RS from a plurality of RSs. Thesecond RS may be a second SS/PBCH block and/or a second CSI-RS. Thesecond RS may be associated with (e.g., correspond to) a second PRACHresource of the one or more PRACH resources configured on the seconduplink BWP, for example, based on the one or more associations. Thesecond PRACH resource may comprise at least one second preamble and/orat least one second PRACH occasion (e.g., time, frequency, code) on thesecond uplink BWP. The wireless device may perform a second randomaccess preamble transmission, for example, if the wireless deviceperforms the second random access resource selection. The wirelessdevice may send (e.g., transmit), in a third slot, the at least onesecond preamble via the at least one second PRACH resource of the seconduplink BWP for the random access procedure, for example, via the secondrandom access preamble transmission.

A wireless device may start (e.g., initiate) a contention resolutiontimer (e.g., ra-ContentionResolutionTimer) or fallback to random accessresource selection, for example, if the Listen-Before-Talk (LBT)procedures on the uplink resources are unsuccessful. The uplinkresources may be used to send (e.g., transmit) one or more transportblocks (e.g., Msg3). The wireless device may monitor multiple randomaccess responses, each associated with an uplink grant. The wirelessdevice may consume more power and network traffic may be increased as aresult of the multiple random access responses.

A base station may communicate/indicate (e.g., identify) one or moreuplink resources to the wireless device. The one or more uplinkresources may be for sending (e.g., transmitting) one or more messages.The one or more uplink resources may be indicated via additional fieldsin existing random access responses. The base station may send (e.g.,transmit) a single random-access response that indicates (e.g.,identifies) multiple uplink resources for sending (e.g., transmitting)one or more messages. The base station may increase the probability of asuccessful LBT procedure, for example, by sending (e.g., transmitting) asingle random-access response that indicates (e.g., identifies) multipleuplink resources for sending (e.g., transmitting) messages.

FIG. 24A and FIG. 24B show examples of a response to a resource request.For example, a wireless device may receive a random access response.Receiving the random access response may comprise completing thereception of the random access response successfully.

FIG. 24A shows a random access response. The random access response maycomprise an UL grant (e.g., RAR UL grant). The random access responsemay also comprise a first field (e.g., Repetition number, Retransmissionnumber, Maximum LBT number, etc.) and/or a second field (e.g., anoffset, time offset, frequency offset, and/or the like). The first fieldmay indicate a quantity/number of one or more uplink transmissionopportunities for an uplink transmission (e.g., msg3, PUSCH) scheduledby the UL grant. The first field may be a first quantity (e.g., number)of bits (e.g., 2 bits, 3 bits, 4 bits, 5 bits). As shown in FIG. 24A,the first field may be 5 bits. The second field may indicate an offset(e.g., time and/or frequency offset) between consecutive uplinktransmission opportunities corresponding to the one or more uplinktransmission opportunities. The second field may be a second quantity(e.g., number) of bits (e.g., 2 bits, 3 bits, 4 bits, 5 bits). Followingthe example described above, the second field may be 3 bits.

FIG. 24B shows an example of a random access response comprising a ULgrant (e.g., RAR UL grant). The UL grant may comprise a first field(e.g., Repetition number, Retransmission number, Maximum LBT number,and/or like) and/or a second field (e.g., an offset, time offset,frequency offset, and/or like). The first field may indicate a quantity(e.g., number) of one or more uplink transmission opportunities for anuplink transmission (e.g., Msg3, PUSCH) scheduled by the UL grant. Thefirst field may be a first quantity (e.g., number) of bits (e.g., 2bits, 3 bits, 4 bits, 5 bits, etc.). As shown in FIG. 24B, the firstfield may be 4 bits. The second field may indicate an offset (e.g., timeand/or frequency offset) between consecutive uplink transmissionopportunities corresponding to the one or more uplink transmissionopportunities. The second field may be a second quantity (e.g., number)of bits (e.g., 2 bits, 3 bits, 4 bits, 5 bits, etc.). Following theexample above, the second field may be 4 bits.

FIG. 25 shows an example of an access procedure. At time T₀ 2502, awireless device 110 may receive one or more messages from a base station120. The one or more messages may comprise one or more configurationparameters of a cell at time T₀ 2502. The one or more configurationparameters may indicate one or more random access channel (PRACH)resources.

At time T₁ 2504, the wireless device 110 may initiate a random accessprocedure (e.g., contention-free random access procedure,contention-based random access procedure) for the cell. The wirelessdevice 110 may perform a random access resource selection for the randomaccess procedure. The wireless device 110 may select a random accesschannel (PRACH) resource from a plurality of PRACH resources in therandom access resource selection. The PRACH resource may comprise atleast one preamble. The PRACH resource may comprise at least one PRACHoccasion (e.g., time resource/occasion, frequency resource/occasion,code, etc.).

At time T₂ 2506, the wireless device 110 may send (e.g., transmit), viathe at least one PRACH occasion, the at least one preamble for therandom access procedure. The wireless device 110 may monitor (e.g.,listen) for a random access response (RAR) corresponding to the at leastone preamble, for example, based on or in response to transmitting theat least one preamble. Monitoring for the RAR may comprise attempting todetect DCI (e.g., DCI format 1_0) during a window (e.g.,ra-responseWindow). The one or more configuration parameters mayindicate the window (e.g., ra-responseWindow). The DCI may be CRCscrambled by an RA-RNTI and/or a C-RNTI.

At time T₃ 2508, the wireless device 110 may detect the DCI (e.g., DCIformat 1_0) within the window. The wireless device 110 may detect afirst transport block in a PDSCH within the window. The DCI may schedulethe first transport block in the PDSCH. A lower layer (e.g., PHY, MAC)of the wireless device 110 may pass the first transport block to ahigher layer of the wireless device (e.g., MAC, RRC), for example, basedon or in response to detecting the first transport block. The wirelessdevice (e.g., the higher layer of the wireless device) may parse thefirst transport block for a random access preamble identity (RAPID).

At time T₃ 2508, the wireless device 110 may receive the random accessresponse corresponding to the at least one preamble. Receiving therandom access response corresponding to the at least one preamble maycomprise a RAPID (e.g., in the first transport block) that indicates(e.g., identifies) the at least one preamble. Receiving the randomaccess response may comprise completing the reception of the randomaccess response successfully. The random access response may comprise anUL grant, a first field (e.g., defined in FIG. 24A), and/or a secondfield (e.g., defined in FIG. 24A). Alternatively, the random accessresponse may comprise an UL grant, a first field (e.g., defined in FIG.24B), and/or a second field (e.g., defined in FIG. 24B). The UL grantmay schedule an uplink transmission (e.g., PUSCH, Msg3) of a transportblock. The wireless device 110 may determine one or more uplinktransmission opportunities (e.g., UL Resource-1 2520, UL resource-22530, and/or UL Resource-3 2540) for the uplink transmission of thetransport block, for example, based on at least one of: the UL grant,the first field, and/or the second field. A transmission opportunity ofthe one or more uplink transmission opportunities may comprise at leastone time and/or at least one frequency resource.

The wireless device 110 may perform one or more LBT procedures on theone or more uplink transmission opportunities (e.g., UL Resource-1 2520,UL resource-2 2530, and/or UL Resource-3 2540). The wireless device mayperform an LBT procedure for each of the one or more uplink transmissionopportunities (e.g., UL Resource-1 2520, UL resource-2 2530, and/or ULResource-3 2540). The wireless device 110 may perform an LBT procedurefor each of the one or more uplink transmission opportunities, forexample, at least until at least one LBT procedure succeeds. Thewireless device 110 may stop performing an LBT procedure on theremaining uplink transmission opportunities, for example, based on or inresponse to the at least one LBT procedure succeeding. The wirelessdevice 110 may perform a first LBT procedure on the UL Resource-1 2520.The wireless device 110 may not perform a second LBT procedure on the ULResource-2 2530 and/or a third LBT procedure on the UL Resource-3 2540,for example, based on or in response to the first LBT procedure beingsuccessful. The wireless device 110 may perform a second LBT procedureon the UL Resource-2 2530, for example, based on or in response to afailure of the first LBT procedure. The wireless device 110 may notperform a third LBT procedure on the UL Resource-3 2540, for example,based on or in response to the second LBT procedure being successful.The wireless device 110 may perform a third LBT procedure on the ULResource-3 2540, for example, based on or in response to a failure ofthe second LBT procedure.

The wireless device 110 may stop performing an LBT procedure on theremaining one or more uplink transmission opportunities, for example, ifthe wireless device 110 determines that at least one LBT procedure ofthe one or more LBT procedures succeeds. The wireless device 110 mayperform the at least one LBT procedure on at least one uplinktransmission opportunity of the one or more uplink transmissionopportunities.

The wireless device 110 may determine at least one LBT procedure on atleast one uplink transmission opportunity succeeded. The wireless device110 may send (e.g., transmit) the transport block for the uplinktransmission via the at least one uplink transmission opportunity, forexample, based on or in response to determining that at least one LBTprocedure succeeded. The wireless device 110 may perform a first LBT onthe UL Resource-1 2520. The wireless device 110 may send (e.g.,transmit) the transport block via the UL Resource-1 2520, for example,based on or in response to the first LBT procedure being successful. Thewireless device 110 may perform a second LBT on the UL Resource-2 2530,for example, based on or in response to a failure of the first LBTprocedure. The wireless device 110 may send (e.g., transmit) thetransport block via the UL Resource-2 2530, for example, based on or inresponse to the second LBT procedure being successful. The wirelessdevice 110 may perform a third LBT procedure on the UL Resource-3 2540,for example, based on or in response to a failure of the second LBTprocedure. The wireless device 110 may send (e.g., transmit) thetransport block via the UL Resource-3 2540, for example, based on or inresponse to the third LBT procedure being successful.

A quantity (e.g., number) of the one or more uplink transmissionopportunities of the wireless device may be three or any otherquantity/number. The wireless device 110 may perform a first LBTprocedure on a first uplink transmission opportunity (e.g., ULResource-1 2520) of the one or more uplink transmission opportunitiesfor the uplink transmission of the transport block. The first LBTprocedure may succeed. The first LBT procedure succeeding may comprisethe wireless device 110 determining a successful first LBT. A successfulfirst LBT procedure may comprise the first uplink transmissionopportunity being idle/unoccupied (e.g., not occupied by anotherwireless device). The wireless device 110 may perform the uplinktransmission of the transport block, for example, based on or inresponse to the first LBT procedure succeeding. Performing the uplinktransmission of the transport block may comprise sending (e.g.,transmitting) the transport block via the first uplink transmissionopportunity (e.g., UL Resource-1 2520). The first uplink transmissionopportunity may comprise a first time allocation (e.g., resource) and/ora first frequency allocation (e.g., resource). The wireless device maynot perform a second LBT procedure on a second uplink transmissionopportunity (e.g., UL Resource-2 2530) for the uplink transmission ofthe transport block, for example, based on or in response to the firstLBT procedure succeeding. The wireless device 110 may not perform athird LBT procedure on a third uplink transmission opportunity (e.g., ULResource-3 2540) for the uplink transmission of the transport block, forexample, based on or in response to the first LBT procedure succeeding.

The first LBT procedure may fail. The wireless device 110 may determine(e.g., detect) a failure of the first LBT procedure. Failure of thefirst LBT may comprise determining (e.g., detecting) that the firstuplink transmission opportunity is busy/occupied (e.g., occupied byanother wireless device). The wireless device 110 may perform a secondLBT procedure on a second uplink transmission opportunity (e.g., ULResource-2 2530) for the uplink transmission of the transport block, forexample, based on or in response to the first LBT procedure failing. Thesecond LBT procedure may succeed. The wireless device 110 may determine(e.g., detect) whether the second LBT procedure is successful. Thewireless device 110 may perform the uplink transmission of the transportblock, for example, based on or in response to the second LBT proceduresucceeding. Performing the uplink transmission of the transport blockmay comprise sending (e.g., transmitting) the transport block via thesecond uplink transmission opportunity. The second uplink transmissionopportunity may comprise a second time allocation (e.g., resource)and/or a second frequency allocation (e.g., resource). The wirelessdevice 110 may not perform a third LBT procedure on a third uplinktransmission opportunity (e.g., UL Resource-3 2540) of for the uplinktransmission of the transport block, for example, based on or inresponse to the second LBT procedure succeeding.

The second LBT procedure may fail. The wireless device 110 may determine(e.g., detect) a failure of the second LBT procedure (e.g., occupied byanother wireless device). The wireless device 110 may perform a thirdLBT procedure on a third uplink transmission opportunity (e.g., ULResource-3 2540) for the uplink transmission of the transport block, forexample, based on or in response to the second LBT procedure failing.The third LBT procedure may succeed. The wireless device 110 maydetermine whether the third LBT procedure is successful. The wirelessdevice 110 may perform the uplink transmission of the transport block,for example, based on or in response to the third LBT proceduresucceeding. Performing the uplink transmission of the transport blockmay comprise sending (e.g., transmitting) the transport block via thethird uplink transmission opportunity. The third uplink transmissionopportunity may comprise a third time allocation (e.g., resource) and/ora third frequency allocation (e.g., resource).

The one or more uplink transmission opportunities may be the firstuplink transmission opportunity (UL Resource-1 2520), the second uplinktransmission opportunity (UL Resource-2 2530) and the third uplinktransmission opportunity (UL Resource-3 2540). The one or more LBTprocedures may be the first LBT procedure, the second LBT procedure, andthe third LBT procedure. The wireless device 110 may perform an LBTprocedure on an uplink transmission opportunity of the one or moreuplink transmission opportunities, for example, if the wireless device110 determines (e.g., detects) LBT procedure failures on previous uplinktransmission opportunities. The previous uplink transmissionopportunities may occur earlier in time and/or frequency than the uplinktransmission opportunity. The wireless device 110 may perform an LBTprocedure on an uplink transmission opportunity, for example, if theuplink transmission opportunity occurs earlier in time than the otheruplink transmission opportunities. The first uplink transmissionopportunity (UL Resource-1 2520) may be the uplink transmissionopportunity that occurs earliest in time among the first uplinktransmission opportunity (UL Resource-1 2520), the second uplinktransmission opportunity (UL Resource-2 2530), and/or the third uplinktransmission opportunity (UL Resource-3 2540). The first uplinktransmission opportunity (UL Resource-1 2520) may be the earlier (e.g.,previous, prior) uplink transmission opportunity for the second uplinktransmission opportunity (UL Resource-2 2530) and/or the third uplinktransmission opportunity (UL Resource-3). The first uplink transmissionopportunity (UL Resource-1 2520) and the second transmission opportunity(UL Resource-2 2530) may be the earlier (e.g., previous, prior) uplinktransmission opportunities for the third uplink transmission opportunity(UL Resource-3 2540).

A quantity (e.g., number) of the one or more uplink transmissionopportunities may be based on the first field in the random accessresponse. The first field may be equal to a first quantity/number. Thefirst quantity/number may be equal to the quantity/number of the one ormore uplink transmission opportunities (e.g., including the transmissionopportunity given by the UL grant), for example, based on or in responseto the first field being equal to the first quantity/number. As shown inFIG. 25 , the quantity/number of the one or more uplink transmissionopportunities may be three (or any other value). Accordingly, the valueof the first field may be three (or any other value). A quantity/numberof the one or more uplink transmission opportunities may be equal to thefirst quantity/number plus one (e.g., the quantity/number may not bebased on the transmission opportunity given by the UL grant), forexample, based on or in response to the first field being equal to afirst quantity/number. The first field may be equal to two and thequantity/number of the one or more uplink transmission opportunities maybe equal to three (e.g., 1 from the UL grant and 2 from the first fieldas additional transmission opportunities) or any other quantity/number.

The UL grant may comprise a first time allocation (e.g., PUSCH timeresource allocation in FIG. 24B). The UL grant may comprise a firstfrequency allocation (e.g., PUSCH frequency resource allocation in FIG.24B). A first resource allocation (e.g., or the first uplinktransmission opportunity) for the uplink transmission of the transportblock may be the first time allocation and/or the first frequencyallocation (e.g., UL resource-1 2520). The wireless device 110 mayperform the first LBT procedure on the first resource allocation. Thewireless device 110 may determine (e.g., detect) a success of the firstLBT. At time T₄ 2510, the wireless device 110 may send (e.g., transmit)the transport block for the uplink transmission via the first frequencyallocation at the first time allocation, for example, based on or inresponse to determining (e.g., detecting) the success of the first LBTprocedure.

The wireless device 110 may determine (e.g., detect) a failure of thefirst LBT procedure. The wireless device 110 may determine a secondresource allocation for the uplink transmission of the transport blockbased on the UL grant and/or the second field, for example, based on orin response to determining the failure of the first LBT procedure. Thesecond field may be a time offset (e.g., slots, symbols, subframe,frames, etc.). The wireless device 110 may determine that the secondresource allocation for the uplink transmission of the transport blockmay be a second time allocation and/or the first frequency allocation(e.g., UL Resource-2 2530), for example, based on or in response to thesecond field being the time offset. The second time allocation may beequal to the first time allocation of the first resource allocation plusthe second field. The wireless device 110 may perform the second LBTprocedure on the second resource allocation. The wireless device 110 maydetermine a success of the second LBT procedure. At time T₅ 2512, thewireless device 110 may send (e.g., transmit) the transport block forthe uplink transmission via the first frequency allocation at the secondtime allocation, for example, based on or in response to determining thesuccess of the second LBT procedure.

The wireless device 110 may determine (e.g., detect) a failure of thesecond LBT procedure. The wireless device 110 may determine a thirdresource allocation for the uplink transmission of the transport blockbased on the UL grant and/or the second field, for example, based on orin response to determining (e.g., detecting) the failure of the secondLBT procedure. The second field may be a time offset (e.g., slots,symbols, subframe, frames, etc.). The wireless device 110 may determinethat the third resource allocation for the uplink transmission of thetransport block may be a third time allocation and/or the firstfrequency allocation (e.g., UL Resource-3 2540), for example, based onor in response the second field being the time offset. The third timeallocation may be equal to the second time allocation of the secondresource allocation plus the second field. The wireless device 110 mayperform a third LBT procedure on the third resource allocation. Thewireless device 110 may determine (e.g., detect) a success of the thirdLBT. At time T₆ 2514, the wireless device 110 may send (e.g., transmit)the transport block for the uplink transmission via the first frequencyallocation at the third time allocation, for example, based on or inresponse to the determining the success of the third LBT procedure.

FIG. 26 shows an example of an access procedure. At time T₀ 2602, awireless device 110 may receive one or more messages from a base station120. The one or more messages may comprise one or more configurationparameters of a cell at time T₀ 2602. The one or more configurationparameters may indicate one or more random access channel (PRACH)resources.

At time T₁ 2604, the wireless device 110 may start (e.g., initiate) arandom access procedure (e.g., contention-free random access procedure,contention-based random access procedure) for the cell. The wirelessdevice 110 may perform a random access resource selection for the randomaccess procedure. The wireless device 110 may determine (e.g., select) arandom access channel (PRACH) resource of the one or more PRACHresources in the random access resource selection. The PRACH resourcemay comprise at least one preamble. The PRACH resource may comprise atleast one PRACH occasion (e.g., time resource/occasion, frequencyresource/occasion, code, etc.).

At time T₂ 2606, the wireless device 110 may send (e.g., transmit), viathe at least one PRACH occasion, the at least one preamble for therandom access procedure. The wireless device 110 may monitor (e.g.,listen) for a random access response (RAR) corresponding to the at leastone preamble, for example, based on or in response to sending (e.g.,transmitting) the at least one preamble. Monitoring (e.g., listening)for the RAR may comprise attempting to detect DCI (e.g., DCI format 1_0)during a window (e.g., ra-responseWindow). The one or more configurationparameters may indicate the window (e.g., ra-responseWindow). The DCImay be CRC scrambled by a RA-RNTI and/or a C-RNTI.

At time T₃ 2608, the wireless device 110 may detect the DCI (e.g., DCIformat 1_0) within the window. The wireless device 110 may detect afirst transport block in a PDSCH within the window. The DCI may schedulethe first transport block in the PDSCH. A lower layer (e.g., PHY, MAC)of the wireless device 110 may pass the first transport block to ahigher layer of the wireless device (e.g., MAC, RRC), for example, basedon or in response to the detecting the first transport block. The higherlayer may parse the first transport block for a random access preambleidentity (RAPID).

At time T₃ 2608, the wireless device 110 may receive the random accessresponse corresponding to the at least one preamble. Receiving therandom access response corresponding to the at least one preamble maycomprise a RAPID (e.g., in the first transport block) that indicates(e.g., identifies) the at least one preamble. Receiving the randomaccess response may comprise completing the reception of the randomaccess response successfully. The random access response may comprise anUL grant, a first field (e.g., defined in FIG. 24A), and/or a secondfield (e.g., defined in FIG. 24A). Alternatively, the random accessresponse may comprise an UL grant, a first field (e.g., defined in FIG.24B), and/or a second field (e.g., defined in FIG. 24B). The UL grantmay schedule an uplink transmission (e.g., PUSCH, Msg3) of a transportblock. The wireless device 110 may determine one or more uplinktransmission opportunities (e.g., UL Resource-1 2620, UL resource-22630, and/or UL Resource-3 2640) for the uplink transmission of thetransport block, for example, based on at least one of: the UL grant,the first field, and/or the second field. A transmission opportunity ofthe one or more uplink transmission opportunities may comprise at leastone time and/or at least one frequency resource.

The wireless device 110 may perform one or more LBT procedures on theone or more uplink transmission opportunities ((e.g., UL Resource-12620, UL resource-2 2630, and/or UL Resource-3 2640). The wirelessdevice may perform an LBT procedure for each of the one or more uplinktransmission opportunities (e.g., UL Resource-1 2620, UL resource-22630, and/or UL Resource-3 2640). The wireless device 110 may perform anLBT procedure for each of the one or more uplink transmissionopportunities, for example, until at least one LBT procedure succeeds.The wireless device 110 may stop performing an LBT procedure on theremaining one or more uplink transmission opportunities, for example,based on or in response to the at least one LBT procedure succeeding.The wireless device 110 may perform a first LBT procedure on the ULResource-1 2620. The wireless device 110 may not perform a second LBTprocedure on the UL Resource-2 2630 and/or a third LBT on the ULResource-3 2640, for example, based on or in response to the first LBTprocedure being successful. The wireless device 110 may perform a secondLBT procedure on the UL Resource-2 2630, for example, based on or inresponse to a failure of the first LBT procedure. The wireless device110 may not perform a third LBT procedure on the UL Resource-3 2640, forexample, based on or in response to the second LBT procedure beingsuccessful. The wireless device 110 may perform a third LBT procedure onthe UL Resource-3 2640, for example, based on or in response to afailure of the first LBT procedure and/or the second LBT procedure.

The wireless device 110 may stop (e.g., cease) performing an LBTprocedure on the remaining one or more uplink transmissionopportunities, for example, if the wireless device 110 determines thatat least one LBT procedure of the one or more LBT procedures succeeds.The wireless device 110 may perform the at least one LBT procedure on atleast one uplink transmission opportunity of the one or more uplinktransmission opportunities.

The wireless device 110 may determine at least one LBT procedure on atleast one uplink transmission opportunity succeeded. The wireless device110 may send (e.g., transmit) the transport block for the uplinktransmission via the at least one uplink transmission opportunity, forexample, based on or in response to determining that at least one LBTprocedure succeeded. The wireless device 110 may perform a first LBTprocedure on the UL Resource-1 2620. The wireless device 110 may send(e.g., transmit) the transport block via the UL Resource-1 2620, forexample, based on or in response to the first LBT procedure beingsuccessful. The wireless device 110 may perform a second LBT procedureon the UL Resource-2 2630, for example, based on or in response to afailure of the first LBT procedure. The wireless device 110 may send(e.g., transmit) the transport block via the UL Resource-2 2630, forexample, based on or in response to the second LBT procedure beingsuccessful. The wireless device 110 may perform a third LBT procedure onthe UL Resource-3 240, for example, based on or in response to a failureof the second LBT procedure. The wireless device 110 may send (e.g.,transmit) the transport block via the UL Resource-3 2640, for example,based on or in response to the third LBT procedure being successful.

A quantity (e.g., number) of the one or more uplink transmissionopportunities of the wireless device may be three. The wireless device110 may perform a first LBT procedure on a first uplink transmissionopportunity (e.g., UL Resource-1 2620) of the one or more uplinktransmission opportunities for the uplink transmission of the transportblock. The first LBT procedure may succeed. The first LBT proceduresucceeding may comprise the wireless device 110 determining (e.g.,detecting) a successful first LBT procedure. A successful first LBTprocedure may comprise the first uplink transmission opportunity beingidle (e.g., not occupied by another wireless device). The wirelessdevice 110 may perform the uplink transmission of the transport block,for example, based on or in response to the first LBT proceduresucceeding. Performing the uplink transmission of the transport blockmay comprise sending (e.g., transmitting) the transport block via thefirst uplink transmission opportunity (e.g., UL Resource-1 2620). Thefirst uplink transmission opportunity may comprise a first timeallocation (e.g., resource) and/or a first frequency allocation (e.g.,resource). The wireless device may not perform a second LBT procedure ona second uplink transmission opportunity (e.g., UL Resource-2 2630) forthe uplink transmission of the transport block, for example, based on orin response to the first LBT procedure succeeding. The wireless device110 may not perform a third LBT procedure on a third uplink transmissionopportunity (e.g., UL Resource-3 2640) for the uplink transmission ofthe transport block, for example, based on or in response to the firstLBT procedure succeeding.

The first LBT procedure may fail. The wireless device 110 may determine(e.g., detect) a failure of the first LBT procedure. Failure of thefirst LBT procedure failing may comprise determining (e.g., detecting)that the first uplink transmission opportunity is busy (e.g., occupiedby another wireless device). The wireless device 110 may perform asecond LBT procedure on a second uplink transmission opportunity (e.g.,UL Resource-2 2630) for the uplink transmission of the transport block,for example, based on or in response to the first LBT procedure failing.The second LBT procedure may succeed. The wireless device 110 maydetermine whether the second LBT procedure is successful. The wirelessdevice 110 may perform the uplink transmission of the transport block,for example, based on or in response to the second LBT proceduresucceeding. Performing the uplink transmission of the transport blockmay comprise sending (e.g., transmitting) the transport block via thesecond uplink transmission opportunity. The second uplink transmissionopportunity may comprise a second time allocation (e.g., resource)and/or a second frequency allocation (e.g., resource). The wirelessdevice 110 may not perform a third LBT procedure on a third uplinktransmission opportunity (e.g., UL Resource-3 2640) of for the uplinktransmission of the transport block, for example, based on or inresponse to the second LBT procedure succeeding.

The second LBT procedure may fail. The wireless device 110 may determine(e.g., detect) a failure of the second LBT procedure (e.g., occupied byanother wireless device). The wireless device 110 may perform a thirdLBT on a third uplink transmission opportunity (e.g., UL Resource-32640) for the uplink transmission of the transport block, for example,based on or in response to the second LBT failing. The third LBTprocedure may succeed. The wireless device 110 may determine whether thethird LBT procedure is successful. The wireless device 110 may performthe uplink transmission of the transport block, for example, based on orin response to the third LBT procedure succeeding. Performing the uplinktransmission of the transport block may comprise sending (e.g.,transmitting) the transport block via the third uplink transmissionopportunity. The third uplink transmission opportunity may comprise athird time allocation (e.g., resource) and/or a third frequencyallocation (e.g., resource).

As noted above, the one or more uplink transmission opportunities may bethe first uplink transmission opportunity (UL Resource-1 2620), thesecond uplink transmission opportunity (UL Resource-2 2630), and/or thethird uplink transmission opportunity (UL Resource-3 2640). The one ormore LBT procedures may be the first LBT procedure, the second LBTprocedure, and/or the third LBT procedure. The wireless device 110 mayperform an LBT procedure on an uplink transmission opportunity of theone or more uplink transmission opportunities, for example, if thewireless device 110 determines (e.g., detects) LBT failures on previousuplink transmission opportunities. The previous uplink transmissionopportunities may occur earlier in time and/or frequency than the uplinktransmission opportunity. The wireless device 110 may perform an LBTprocedure on an uplink transmission opportunity, for example, if theuplink transmission opportunity occurs earlier in time than the otheruplink transmission opportunities. The first uplink transmissionopportunity (UL Resource-1 2620) may be the uplink transmissionopportunity that occurs earliest in time among the first uplinktransmission opportunity (UL Resource-1 2620), the second uplinktransmission opportunity (UL Resource-2 2630), and the third uplinktransmission opportunity (UL Resource-3 2640). The first uplinktransmission opportunity (UL Resource-1 2620) may be the earlier (e.g.,previous, prior) uplink transmission opportunity for the second uplinktransmission opportunity (UL Resource-2 230) and/or the third uplinktransmission opportunity (UL Resource-3 2640). The first uplinktransmission opportunity (UL Resource-1 2620) and the secondtransmission opportunity (UL Resource-2 2630) may be the earlier (e.g.,previous, prior) uplink transmission opportunities for the third uplinktransmission opportunity (UL Resource-3 2640).

A quantity/number of the one or more uplink transmission opportunitiesmay be based on the first field in the random access response. The firstfield may be equal to a first quantity/number. The first quantity/numbermay be equal to the quantity/number of the one or more uplinktransmission opportunities (e.g., including the transmission opportunitygiven by the UL grant), for example, based on or in response to thefirst field being equal to the first quantity/number. As shown in FIG.26 , the quantity/number of the one or more uplink transmissionopportunities may be three (or any other value). Accordingly, the valueof the first field may be three (or any other value). A quantity/numberof the one or more uplink transmission opportunities may be equal to thefirst quantity/number plus one (e.g., the number may not be based on thetransmission opportunity given by the UL grant), for example, based onor in response to the first field being equal to a firstquantity/number. The first field may be equal to two (or any otherquantity/number). The quantity/number of the one or more uplinktransmission opportunities may be equal to three (e.g., 1 from the ULgrant and 2 from the first field as additional transmissionopportunities) or any other value.

The UL grant may comprise a first time allocation (e.g., PUSCH timeresource allocation in FIG. 24B). The UL grant may comprise a firstfrequency allocation (e.g., PUSCH frequency resource allocation in FIG.24B). A first resource allocation (e.g., or the first uplinktransmission opportunity) for the uplink transmission of the transportblock may be the first time allocation and/or the first frequencyallocation (e.g., UL resource-1 2620). The wireless device 110 mayperform the first LBT procedure on the first resource allocation. Thewireless device 110 may determine (e.g., detect) a success of the firstLBT procedure. At time T₄ 2610, the wireless device 110 may send (e.g.,transmit) the transport block for the uplink transmission via the firstfrequency allocation at the first time allocation, for example, based onor in response to determining (e.g., detecting) the success of the firstLBT procedure.

The wireless device 110 may determine a failure of the first LBTprocedure. The wireless device 110 may determine a second resourceallocation for the uplink transmission of the transport block based onthe UL grant and/or the second field, for example based on or inresponse to the determining the failure of the first LBT procedure. Thesecond field may be a frequency offset (e.g., subcarriers, resourceblocks, subbands, BWPs, etc.). The wireless device 110 may determinethat the second resource allocation for the uplink transmission of thetransport block is the first time allocation and/or a second frequencyallocation (e.g., UL Resource-2 2630), for example, based on or inresponse to the second field being the frequency offset. The secondfrequency allocation may be equal to the first frequency allocation ofthe first resource allocation plus the second field (e.g., the frequencyoffset). The wireless device 110 may perform the second LBT procedure onthe second resource allocation (e.g., UL Resource-2 2630). The wirelessdevice 110 may determine (e.g., detect) a success of the second LBTprocedure. At time T₄ 2610, the wireless device 110 may send (e.g.,transmit) the transport block for the uplink transmission via the secondfrequency allocation at the first time allocation, for example, based onor in response to the determining (e.g., detecting) that the second LBTprocedure was successful.

The wireless device 110 may determine a failure of the second LBTprocedure. The wireless device 110 may determine a third resourceallocation for the uplink transmission of the transport block based onthe UL grant and/or the second field, for example, based on or inresponse to the determining (e.g., detecting) the failure of the secondLBT procedure. The second field may be a frequency offset (e.g.,subcarriers, resource blocks, subbands, BWPs, etc.). The wireless device110 may determine that the third resource allocation for the uplinktransmission of the transport block may be the first time allocationand/or a third frequency allocation (e.g., UL Resource-3 2640), forexample, based on or in response to the second field being the frequencyoffset. The third frequency allocation may be equal to the secondfrequency allocation of the second resource allocation (e.g., ULResource-2 2630) plus the second field (e.g., frequency offset). Thewireless device 110 may perform the third LBT procedure on the thirdresource allocation. The wireless device may determine whether the thirdLBT procedure is a success. At time T₄ 2610, the wireless device 110 maysend (e.g., transmit) the transport block for the uplink transmissionvia the third frequency allocation at the first time allocation, forexample, based on or in response to determining (e.g., detecting) thatthe third LBT procedure was a success.

By including the first field and/or the second field in the randomaccess response may increase the success probability of the uplinktransmission scheduled by the random access response. Including the ULgrant of the random access response may increase the success probabilityof the uplink transmission scheduled by the random access response.Including the first field and/or the second field in the random accessresponse may increase transmission opportunities for the uplinktransmission and/or reduce the probability of LBT failure. Including theUL grant of the random access response may increase transmissionopportunities for the uplink transmission and/or reduce the probabilityof LBT failure

At least two uplink opportunities may overlap in time (e.g., in at leastone symbol, slot, and/or subframe). Additionally or alternatively, atleast two LBT procedures on the at least two uplink opportunities maysucceed. In FIG. 26 , the first uplink transmission opportunity (e.g.,UL Resource-1 2620), the second uplink transmission opportunity (e.g.,UL Resource-2 2630), and/or the third uplink transmission opportunity(e.g., UL Resource-3 2640) may overlap. At time T₄ 2610, the wirelessdevice 110 may perform the first LBT procedure, the second LBTprocedure, and/or the third LBT procedure. The first LBT procedure andthe third LBT may succeed, while the second LBT procedure may fail. Thewireless device 110 may determine (e.g., select) an uplink transmissionopportunity (e.g., the first transmission opportunity or the thirduplink transmission opportunity) of the at least two uplinkopportunities, for example, based on or in response to the at least twoLBT procedures on the at least two uplink opportunities succeeding(e.g., the first LBT procedure on the first transmission opportunityand/or the third LBT procedure on the third uplink transmissionopportunity). The wireless device 110 may determine (e.g., select) anuplink transmission opportunity (e.g., the first transmissionopportunity or the third uplink transmission opportunity), for example,based on one or more criteria.

The one or more criteria for determining (e.g., selecting) an uplinktransmission opportunity may be based on an index (e.g., BWP index,subband index). The wireless device 110 may determine (e.g., select) theuplink transmission opportunity with the lowest (or highest) index amongthe at least two indices of the at least two uplink opportunities. Thewireless device 110 may determine (e.g., select) the uplink transmissionopportunity, for example, based on or in response to a first index ofthe uplink transmission opportunity being the lowest (or highest) amongthe at least two indices of the at least two uplink opportunities. Theone or more configuration parameters may indicate (e.g., identify) anindex for each of the uplink transmission opportunities. The firstuplink transmission opportunity may be associated with a first indexand/or the third uplink transmission opportunity may be associated witha third index. The wireless device 110 may determine (e.g., select) thethird uplink transmission opportunity, for example, based on or inresponse to the third index being lower (or higher) than the firstindex.

The one or more criteria for determining (e.g., selecting) an uplinktransmission opportunity may be based on an uplink transmission power.The wireless device 110 may determine (e.g., select) the uplinktransmission opportunity with the lowest (or highest) transmission poweramong the at least two uplink transmission powers of the at least twouplink opportunities. The wireless device 110 may determine (e.g.,select) an uplink transmission opportunity, for example, based on or inresponse to a first uplink transmission power associated with the uplinktransmission opportunity being lower (or higher) than the uplinktransmission powers of the other uplink transmission opportunities.

The one or more criteria for determining (e.g., selecting) an uplinktransmission opportunity may be based on an operating frequency (e.g.,frequency allocation and/or frequency band). The wireless device 110 maydetermine (e.g., select) the uplink transmission opportunity with thelowest (or highest) operating frequency among a plurality of uplinkoperating frequencies associated with each of the uplink transmissionopportunities. The wireless device 110 may determine (e.g., select) theuplink transmission opportunity, for example, based on or in response toa first uplink operating frequency of the uplink transmissionopportunity being lower (or higher) than the uplink operatingfrequencies associated with each of the uplink opportunities. Thewireless device 110 may determine that the frequency allocation of thefirst transmission opportunity may be lower (or higher) than the thirdfrequency allocation of the third uplink transmission opportunity. Thewireless device 110 may determine (e.g., select) the first uplinktransmission opportunity, for example, based on or in response todetermining that the frequency allocation of the first transmissionopportunity may be lower (or higher) than the third frequency allocationof the third uplink transmission opportunity.

A wireless device may start a contention resolution timer associatedwith an access procedure. The wireless device may start the contentionresolution timer, for example, based on or in response to transmitting afirst message for the access procedure. The wireless device may monitorfor a second message rescheduling the transmission of the first messageat a time that the contention resolution timer is running, for example,if the base station fails to receive the first message. The wirelessdevice may fallback to resource selection, for example, if thecontention resolution timer expires and/or if the wireless device hasnot received the second message from the base station. The wirelessdevice may retransmit a message, for example, if the wireless devicefalls back to resource selection. The wireless device may not send(e.g., transmit) the message, for example, based on a failedlisten-before-talk (LBT) procedure. For example, the resource totransmit the message may be unavailable/occupied. The wireless devicemay not know when to start the contention resolution timer, for example,if the message cannot be sent (e.g., transmitted). For example, an LBTprocedure may fail, which may result in the message not being sent(e.g., transmitted). The wireless device may not start the contentionresolution timer, for example, at least until the message is sent (e.g.,transmitted). The wireless device may monitor the for the second messageto reschedule the first message, for example, if the contentionresolution timer is running. The wireless device may not monitor for aretransmission grant, for example, if the contention resolution timer isnot running. The contention resolution timer may not expire, forexample, if it is not running. The wireless device may not fall back toa resource selection of the access procedure, for example, if thecontention resolution timer does not expire. The wireless device may berequired to continue to perform the access procedure.

As described herein, a wireless device may perform one or morelisten-before-talk (LBT) procedures on one or more uplink grants, forexample, before sending (e.g., transmitting) one or more transportblocks. The wireless device may start a contention resolution timer, forexample, based on or in response to the one-or-more LBT proceduresfailing. The wireless device may perform a random access selection, forexample, based on or in response to the one-or-more LBT proceduresfailing. A fixed RV sequence may be determined/defined, for example, foruse if one or more LBT procedures fail. One or more fallback proceduresmay be determined/defined, for example, for use if one or more LBTprocedures fails. By using the fixed RV sequence and/or the one or morefallback procedures, for example, if one or more LBT procedures fail,latency may be reduced/avoided and/or misalignment between a wirelessdevice and a base station may be reduced/avoided.

FIG. 27 shows an example of an access procedure. The steps and/orprocedures performed at times T₀ 2702, T₁ 2704, and/or T₂ 2706 may besimilar to the steps and/or procedures performed at times T₀ 2502, T₁2504, and/or T₂ 2506.

At time T₀ 2702, a wireless device 110 may receive one or more messagesfrom a base station 120. The one or more messages may comprise one ormore configuration parameters of a cell. The one or more configurationparameters may indicate one or more random access channel (PRACH)resources and/or a contention-resolution timer (e.g.,ra-ContentionResolutionTimer).

At time T₁ 2704, the wireless device 110 may start (e.g., initiate) arandom access procedure for the cell. The wireless device 110 mayperform a first random access resource selection, for example, based onor in response to starting (e.g., initiating) the random accessprocedure. The wireless device 110 may determine (e.g., select) a randomaccess channel (PRACH) resource of the one or more PRACH resources forthe first random access selection. The PRACH resource may comprise atleast one preamble. The PRACH resource may comprise at least one PRACHoccasion (e.g., time resource/occasion, frequency resource/occasion,code, etc.).

At time T₂ 2706, the wireless device 110 may send (e.g., transmit) theat least one preamble for the random access procedure via the at leastone PRACH occasion. The wireless device 110 may monitor (e.g., listen)for a random access response (RAR) corresponding to the at least onepreamble, for example, based on or in response to the transmitting theat least one preamble. Monitoring for the RAR may comprise attempting todetect DCI (e.g., DCI format 1_0) during a window (e.g.,ra-responseWindow). The one or more configuration parameters mayindicate the window for the RAR.

At time T₃ 2708, the wireless device 110 may receive the random accessresponse corresponding to the at least one preamble. The random accessresponse may comprise at least two uplink grants for an uplinktransmission of a transport block (e.g., PUSCH, Msg3). Each of the atleast two uplink grants may comprise a time allocation (e.g., PUSCH timeresource allocation in FIG. 24B) and/or a frequency allocation (e.g.,PUSCH frequency resource allocation in FIG. 24B). As shown in FIG. 27 ,the random access response may comprise three uplink grants (e.g.,indicating UL Resource-1 2720, UL Resource-2 2730, UL Resource-3 2740)for the uplink transmission of the transport block. A first uplink grantof the at least two uplink grants may comprise a first time allocationand/or a first frequency allocation (e.g., UL Resource-1 2720). A seconduplink grant of the at least two uplink grants may comprise a secondtime allocation and/or a second frequency allocation (e.g., ULResource-2 2730). A third uplink grant of the at least two uplink grantsmay comprise a third time allocation and/or a third frequency allocation(e.g., UL Resource-3 2740).

The random access response may comprise at least two uplink transmissionopportunities for an uplink transmission (e.g., PUSCH, Msg3). Each ofthe at least two uplink transmission opportunities may comprise a timeallocation (e.g., PUSCH time resource allocation in FIG. 24B) and/or afrequency allocation (e.g., PUSCH frequency resource allocation in FIG.24B). As shown in FIG. 27 , the random access response may comprisethree uplink transmission opportunities (e.g., UL Resource-1 2720, ULResource-2 2730, UL Resource-3 2740) for the uplink transmission of thetransport block. A first uplink transmission opportunity may comprise afirst time allocation and/or a first frequency allocation (e.g., ULResource-1 2720). A second uplink transmission opportunity may comprisea second time allocation and/or a second frequency allocation (e.g., ULResource-2 2730). A third uplink transmission opportunity may comprise athird time allocation and/or a third frequency allocation (e.g., ULResource-3 2740).

The wireless device 110 may perform one or more LBT procedures on theone or more uplink resources indicated by the at least two uplinkgrants. The wireless device 110 may perform one or more LBT procedureson the one or more uplink resources indicated by the at least two uplinktransmission opportunities. As shown in FIG. 27 , the wireless device110 may perform a first LBT on the first time allocation and/or thefirst frequency allocation indicated by the first UL grant (or by thefirst uplink transmission opportunity). The wireless device 110 mayperform a second LBT on the second time allocation and/or the secondfrequency allocation indicated by the second UL grant (or by the seconduplink transmission opportunity). The wireless device 110 may perform athird LBT on the third time allocation and/or the third frequencyallocation indicated by the third UL grant (or by the third uplinktransmission opportunity). The wireless device 110 may determine (e.g.,detect) a failure of the one or more LBT procedures on the one or moreuplink resources indicated by the at least two uplink grants.

At time T₄ 2710, the wireless device 110 may determine (e.g., detect) afailure of the first LBT procedure. At time T₅ 2712, the wireless 110device may determine (e.g., detect) a failure of the second LBTprocedure. At time T₆ 2714, the wireless device 110 may determine (e.g.,detect) a failure of the third LBT procedure in FIG. 27 . The wirelessdevice 110 may start a contention resolution timer (e.g.,ra-ContentionResolutionTimer), for example, based on or in response tothe failure of the one or more LBT procedures.

The contention-resolution timer (e.g., ra-ContentionResolutionTimer) mayexpire. The wireless device 110 may perform a second random accessresource selection, for example, based on or in response to thecontention resolution timer (e.g., ra-ContentionResolutionTimer)expiring. The wireless device 110 may determine (e.g., select) a secondPRACH resource of the one or more PRACH resources, for example, duringthe second random access resource selection. The second PRACH resourcemay comprise at least one second preamble and/or at least one secondPRACH occasion (e.g., time, frequency, code, etc.). The wireless device110 may send (e.g., transmit) the at least one second preamble via theat least one second PRACH occasion for the random access procedure, forexample, based on or in response to determining (e.g., selecting) thesecond PRACH resource.

The wireless device 110 may perform a second random access resourceselection, for example, based on or in response to the failure of theone or more LBT procedures. The wireless device 110 may determine (e.g.,select) a second PRACH resource of the one or more PRACH resources, forexample, during the second random access resource selection. The secondPRACH resource may comprise at least one second preamble and/or at leastone second PRACH occasion (e.g., time, frequency, code, etc.). Thewireless device 110 may send (e.g., transmit) the at least one secondpreamble via the at least one second PRACH occasion for the randomaccess procedure, for example, based on or in response to determining(e.g., selecting) the second PRACH resource.

The wireless device 110 may not stop the window (e.g.,ra-responseWindow), for example, if the wireless device 110 receives therandom access response. The wireless device 110 may perform an LBTprocedure (e.g., first LBT, second LBT or third LBT) to send (e.g.,transmit) the transport block for the uplink transmission. The wirelessdevice 110 may determine whether an LBT procedure is successful. Thewireless device 110 may stop (e.g., cease, pause, halt) the window(e.g., ra-responseWindow), for example, based on or in response todetermining (e.g., detecting) the success of the LBT procedure. Thewireless device 110 may send (e.g., transmit) the transport block forthe uplink transmission, for example, based on or in response todetermining (e.g., detecting) that one of the LBT procedures wassuccessful. The wireless device 110 may stop (e.g., cease, pause, halt)the window (e.g., ra-responseWindow), for example, based on or inresponse to sending (e.g., transmitting) the transport block.

FIG. 28 shows an example flowchart of an access procedure. At step 2810,a wireless device may receive one or more messages comprising one ormore configuration parameters for a cell. The one or more messages maybe received from a base station. The one or more configurationparameters may indicate one or more random access channel (PRACH)resources and/or a contention resolution timer (e.g.,ra-ContentionResolutionTimer).

At step 2820, the wireless device may start (e.g., initiate) a randomaccess procedure (e.g., contention-free random access procedure,contention-based random access procedure) for the cell. The wirelessdevice may determine (e.g., select) a random access channel (PRACH)resource of the one or more PRACH resources as part of a random accessresource selection process. The wireless device may send (e.g.,transmit) at least one preamble for the random access procedure via atleast one RACH (e.g., time-frequency) occasion. The wireless device maymonitor (e.g., listen) for a random access response (RAR) correspondingto the at least one preamble, for example, based on or in response tosending (e.g., transmitting) the at least one preamble.

At step 2830, the wireless device may perform a random access resourceselection. The wireless device may determine (e.g., select) a randomaccess channel (RACH) resource, for example, as part of the randomaccess resource selection. The RACH resource may comprise at least onepreamble. The RACH resource may comprise at least one RACH occasion(e.g., time resource/occasion, frequency resource/occasion, code, etc.).The wireless device may send (e.g., transmit) a preamble via the atleast one RACH occasion. At step 2840, the wireless device may receivethe random access response corresponding to the at least one preamble.The random access response may comprise at least two UL grants. At step2850, the wireless device may perform one or more LBT procedures onuplink resources associated with each of the at least two UL grants. Atstep 2860, the wireless device may determine whether the LBT procedureson the uplink resources associated with each of the at least two ULgrants failed. As discussed above, an LBT procedure may fail, forexample, if a resource (e.g., uplink resource) is busy/occupied (e.g.,occupied by another device). At step 2865, the wireless device mayperform an uplink transmission via one of the at least two UL resources,for example, if one of the LBT procedures was successful (e.g., was notoccupied by another device). Performing the uplink transmission maycomprise sending (e.g., transmitting) one or more transport blocks viathe uplink resource.

At step 2870, the wireless device may start (e.g., commence, initiate)the contention resolution timer (e.g., ra-ContentionResolutionTimer).The contention resolution timer may be started, for example, if each ofthe LBT procedures failed. Additionally or alternatively, the contentionresolution timer may be started, for example, based on or in response tothe wireless device sending (e.g., transmitting) one or more transportblocks via the at least one uplink grant. At step 2880, the wirelessdevice may determine (e.g., detect) whether the contention resolutiontimer (e.g., ra-ContentionResolutionTimer) has expired. The wirelessdevice may continue to monitor for a DCI (e.g., Msg3 and/or Msg 4retransmission), for example, if the contention resolution timer (e.g.,ra-ContentionResolutionTimer) has not expired. The wireless device mayfall back to a new random access resource selection procedure, forexample, if the contention resolution timer expires and/or the wirelessdevice has not received one or more messages in response to the one ormore transport blocks sent (e.g., transmitted) by the wireless device.The wireless device may fallback and perform a new random accessresource selection procedure, for example, if the contention resolutiontimer expires and/or the wireless device has not received one or moremessages in response to the one or more transport blocks sent(transmitted) by the wireless device.

FIG. 29 shows an example flowchart of an access procedure. At step 2910,a wireless device may receive one or more messages comprising one ormore configuration parameters for a cell. The one or more messages maybe received from a base station. The one or more configurationparameters may indicate one or more random access channel (PRACH)resources and/or a contention resolution timer (e.g.,ra-ContentionResolutionTimer).

At step 2920, the wireless device may start (e.g., initiate) a randomaccess procedure (e.g., contention-free random access procedure,contention-based random access procedure) for the cell. The wirelessdevice may determine (e.g., select) a random access channel (PRACH)resource of the one or more PRACH resources as part of a random accessresource selection process. The wireless device may send (e.g.,transmit) at least one preamble for the random access procedure via atleast one RACH (e.g., time-frequency) occasion. The wireless device maymonitor (e.g., listen) for a random access response (RAR) correspondingto the at least one preamble, for example, based on or in response tosending (e.g., transmitting) the at least one preamble.

At step 2930, the wireless device may perform a random access resourceselection. The wireless device may determine (e.g., select) a randomaccess channel (RACH) resource, for example, as part of the randomaccess resource selection. The RACH resource may comprise at least onepreamble. The RACH resource may comprise at least one RACH occasion(e.g., time resource/occasion, frequency resource/occasion, code, etc.).The wireless device may send (e.g., transmit) a preamble via the atleast one RACH occasion.

At step 2940, the wireless device may receive the random access responsecorresponding to the at least one preamble. The random access responsemay comprise at least two UL grants. At step 2950, the wireless devicemay perform one or more LBT procedures on uplink resources associatedwith each of the at least two UL grants. At step 2960, the wirelessdevice may determine whether the LBT procedures on the uplink resourcesassociated with each of the at least two UL grants failed. As discussedabove, an LBT procedure may fail, for example, if a resource (e.g.,uplink resource) is busy/occupied (e.g., occupied by another device).The wireless device may perform a new random access resource selectionin step 2930, for example, if each of LBT procedures performed on theuplink resources fails. At step 2970, the wireless device may perform anuplink transmission via one of the at least two UL resources, forexample, if one of the LBT procedures was successful (e.g., was notbusy). Performing the uplink transmission may comprise sending (e.g.,transmitting) one or more transport blocks via the uplink resource. Atstep 2980, the wireless device may start (e.g., initiate, commence) thecontention resolution timer (e.g., ra-ContentionResolutionTimer). Thecontention resolution timer may be started (e.g., initiated, commenced),for example, based on or in response to the wireless device sending(e.g., transmitting) one or more transport blocks via the at least oneuplink grant.

A wireless device may perform an initial transmission of a message of anaccess procedure with an RV equal to zero. Re-sending (e.g.,re-transmitting) the message may be scheduled by the base station viainformation indicating a value of the RV for resending (e.g.,retransmitting). In a two-step random access procedure, the wirelessdevice may transmit a plurality of messages in the first step of thetwo-step random access procedure. The base station may not be aware ofthe two-step random access procedure, for example, if the base stationcannot decode a first message. The base station may not reschedule asecond message for re-sending (e.g., re-transmission), for example,because the base station may not be aware of the second message. Thewireless device may select an RV for the second message retransmission.However, the base station may not decode the second message, forexample, if the RV value is not known at the base station. Thisoperation may increase the latency of the two-step random accessprocedure. Further, the number of retransmissions without successfulreception at the base station may increase uplink interference withother cells and/or wireless devices.

A wireless device may initially send (e.g., transmit) a message with afirst redundancy version (RV), for example, if the wireless deviceinitiates a random access procedure. Re-sending (e.g., re-transmission)of the message may be scheduled by the base station via controlinformation. The control information may indicate the number of the RVused for re-sending (e.g., re-transmitting) the message. Using differentRV numbers for re-sending (e.g., re-transmitting) the message mayincrease successful decoding probability of the message, for example, bypermitting the base station to combine different RV sequences (e.g., byenhancing energy at each combining).

A wireless device may send (e.g., transmit) a random access preamble anda transport block in the first step of the two-step random accessprocedure, for example, if the wireless device initiates a two-stepcontention-free random access procedure. The wireless device may send(e.g., transmit) the transport block with a first RV. Misalignmentbetween the wireless device and the base station may be avoided, forexample, if the base station is aware that retransmissions may beperformed with an RV. The probability of successful reception at thebase station may also be increased, for example, if sending/re-sending(e.g., transmitting/re-transmitting) with an RV.

The base station may not receive the preamble and the transport block.Therefore, the base station may not transmit a random access response.The wireless device may re-send (e.g., re-transmit) the preamble and thetransport block, for example, if wireless device does not receive therandom access response. The wireless device may retransmit the transportblock with a second RV different from the first RV, for example, if thebase station and wireless device determine/agree that the random accessprocedure is a contention-free random access procedure. The base stationmay combine the first RV and the second RV to increase the energy of thetransport block. This combining may increase the decoding probability ofthe transport block leading to fast completion of the random accessprocedure. The base station may combine the retransmissions resulting incode rate gain, for example, as additional parity and redundantinformation bits are transmitted in each retransmission. The basestation may gain extra information of the transport block at eachretransmission.

A wireless device may send (e.g., transmit) a first message and a secondmessage in the first step of a two-step random access procedure, forexample, if the wireless device initiates the two-step random accessprocedure. The base station may transmit a regular (e.g., legacy) RAR tothe wireless device, for example, if the base station can only detectthe first message. The wireless device may fall back to a four-steprandom access, for example, based on receiving the regular RAR. Thewireless device may not know which RV to use to send (e.g., transmit)the second message of the four-step random access procedure.

As described herein, a wireless device may re-send (e.g., re-transmit) atransport block with the RV equal to zero, for example, if the randomaccess procedure is a two-step random access procedure or a four-steprandom access procedure. The wireless device may send (e.g., transmit)one or more transport blocks with an RV equal to zero, for example, ifthe wireless device falls-back to 4-step RACH procedure. By using RVequal zero in transmissions/retransmissions of a transport block,latency may be reduced.

A base station may send (e.g., transmit) one or more downlink controlsignals and/or messages to the wireless device, which may indicate afixed redundancy version (RV) sequence to use for re-sending (e.g.,re-transmitting) one or more transport blocks during a two-step randomaccess procedure. A wireless device may re-send (e.g., re-transmit) theone or more transport blocks based on the fixed RV sequence, forexample, if the two-step random access procedure is a contention-freerandom access procedure. The wireless device may re-send (e.g.,re-transmit) the one or more transport blocks with an RV equal to zero(0), for example, if the two-step random access procedure is acontention-based random access procedure or if the wireless device fallsback to a four-step random access procedure as described above.

In RV combining, the wireless device may add additional redundancy bitsto each transmission. This may also be referred to as “implicit linkadaptation.” The wireless device may only retransmit, for example, ifthe previous transmission was not received by the base station. Unlikeexplicit link adaptation, RV combining does not require any channelestimation and therefore, works equally well regardless of the speed atwhich the wireless device may be moving. Additionally, the base stationmay complete reception of the second message (and/or Msg3) earlier, forexample, with RV combining. With an early successful reception of msg3,the wireless device may not need to transmit additional Msg3retransmissions, for example, based on early successful reception ofMsg3. This may result in saving power consumption for the wirelessdevice and/or reduce uplink interference to other wireless devicesand/or cells. The wireless device may complete the two-steprandom-access procedure earlier, for example, based on early successfulMsg3 reception. Two-step random-access procedure may also be initiatedfor a beam failure recovery procedure. The wireless device may send(e.g., transmit) the candidate beam information to the base station, forexample, using one or more transport blocks (e.g., Msg3). The wirelessdevice may not declare radio link failure due to prolonged beam failurerecovery procedure, for example, based on receiving a message from thebase station that indicates that the message was received successfully.

FIG. 30 shows an example of a random access procedure. At time T₀ 3002,a wireless device 110 may receive one or more configuration parametersfrom a base station 120. The configuration parameters may compriseconfiguration parameters for a two-step random access (RA) procedure ofa cell (e.g., PCell, SCell). The one or more configuration parametersmay indicate (e.g., identify) one or more PRACH resources (e.g., PRACHresources in FIG. 30 ). The one or more PRACH resources may comprise oneor more RAPs. The one or more PRACH resources may comprise one or moreRACH occasions (e.g., time/frequency occasion). The one or moreconfiguration parameters may indicate (e.g., identify) one or moreuplink radio resources (in terms of time, frequency,code/sequence/signature). The configuration parameters may comprise oneor more uplink radio resources (e.g., Uplink resources in FIG. 30 ). Theone or more configuration parameters may indicate (e.g., identify) oneor more uplink grants indicating one or more uplink radio resources (interms of time, frequency, code/sequence/signature).

The base station 120 may broadcast one or more uplink radio resources(in terms of time, frequency, code/sequence/signature). A plurality ofwireless devices (in the cell) may share the one or more uplink radioresources, for example, based on or in response to broadcasting the oneor more uplink resources. The one or more configuration parameters mayindicate (e.g., identify) one or more associations (e.g., mappings)between the one or more uplink radio resources and the one or more PRACHresources. The one or more configuration parameters may indicate (e.g.,identify) one or more associations (e.g., mappings) between the one ormore uplink radio resources and the one or more RAPs of the one or morePRACH resources. The one or more configuration parameters may indicate(e.g., identify) one or more associations (e.g., mappings) between theone or more uplink radio resources and the one or more RACH occasions ofthe one or more PRACH resources. The one or more associations (e.g.,mappings) may be one-to-one, many-to-one, one-to-many, and/ormany-to-many as discussed in greater detail below with respect to FIG.31 .

The one or more configuration parameters may indicate (e.g., identify) aredundancy version (RV) sequence (e.g., [0 0 0 0], [0 2 3 1], [0 3 0 3])for the one or more uplink radio resources. As shown in FIG. 30 , theredundancy version sequence may be [0 2 3 1]. A size (e.g., length) ofthe RV sequence may be a first size (e.g., 4). The size (e.g., length)of the RV sequence may be the number of elements in the RV sequence. Thesize of the RV sequence may be four, for example, if the RV sequence [01 2 3]. The first size of the RV sequence may be five, for example, ifthe RV sequence is [0 1 2 3 0].

At time T₁ 3004, the wireless device 110 may start (e.g., initiate) atwo-step random access procedure (e.g., contention-free random accessprocedure, contention-based random access procedure) for the cell. Thewireless device 110 may perform a first random access resourceselection, for example, based on or in response to starting (e.g.,initiating) the two-step random access procedure. The wireless device110 may determine (e.g., select) a random access channel (PRACH)resource of the one or more PRACH resources for the first random accessselection. The PRACH resource may comprise at least one preamble. ThePRACH resource may comprise at least one PRACH occasion (e.g., timeresource/occasion, frequency resource/occasion, code, etc.).

The wireless device may determine (e.g., select) at least one UL radioresource of the one or more uplink radio resources, for example, if thewireless device performs the first random access resource selection forthe two-step random access procedure. The first random access resourceselection may be based on the one or more associations (e.g., mappings).The PRACH resource may be (e.g., one-to-one, one-to-many, many-to-one)associated (e.g., mapped) with the at least one UL radio resource (or atleast one uplink grant). The at least one UL radio resource may comprisea time resource (e.g., occasion) and/or a frequency resource (e.g.,occasion) for an uplink transmission of a transport block (e.g., Msg3,PUSCH). The PRACH resource being associated (e.g., mapped) with the atleast one UL radio resource may comprise the at least one preamble ofthe PRACH resource being associated (e.g., mapped) with the at least oneUL radio resource. The PRACH resource being associated (e.g., mapped)with the at least one UL radio resource may comprise the at least onePRACH occasion of the PRACH resource being associated (e.g., mapped)with the at least one UL radio resource.

At time T₂ 3006, the wireless device 110 may send (e.g., transmit) theat least one preamble for the two-step random access procedure via theat least one PRACH occasion. The at least one preamble may be sent(e.g., transmitted) via the at least one PRACH occasion, for example,based on the first random access selection. At time T₃ 3008, thewireless device 110 may send (e.g., transmit) the transport block forthe uplink transmission for the two-step random access procedure via theat least one UL radio resource. The transport block may be sent (e.g.,transmitted), for example, based on or in response to the determining(e.g., selecting) the at least one UL radio resource. The wirelessdevice 110 may send (e.g., transmit) the transport block with a firstredundancy version (RV) in the RV sequence (e.g., the first RV is 0 inFIG. 30 ). The first RV may have a first index in the redundancy versionsequence. In a redundancy version sequence [0 2 3 1], the first indexmay be equal to 1 if the first RV is 0; the first index may be equal to2 if the first RV is 2; the first index may be equal to 3 if the firstRV is 3; and the first index may be equal to 4 if the first RV is 1. Inanother example with a redundancy version sequence [0 1 2 3], the firstindex may be equal to 1 if the first RV is 0; the first index may beequal to 2 if the first RV is 1; the first index may be equal to 3 ifthe first RV is 2; and the first index may be equal to 4 if the first RVis 3.

Sending (e.g., transmitting) the at least one preamble may overlap intime and/or in frequency (partially or entirely) with the uplinktransmission of the transport block. The at least one PRACH occasion maybe multiplexed with the at least one UL radio resource in the timeand/or frequency domain (e.g., TDM-ed, FDM-ed). The wireless device 110may send (e.g., transmit) the at least one preamble and/or the at leastone UL radio resource simultaneously (e.g., T₂ 3006 and T₃ 3008 may bethe same), for example, if the at least one PRACH occasion ismultiplexed with the at least one UL radio resource in a frequencydomain. The wireless device 110 may send (e.g., transmit) the at leastone preamble and/or the transport block at different times with a timegap (e.g., T₂ 3006 and T₃ 3008 may be different), for example, if the atleast one PRACH occasion is multiplexed with the at least one UL radioresource in a time domain. The wireless device 110 may monitor (e.g.,listen) for a response (e.g., random access response, two-step Msg2,MsgB) from the base station 120, for example, based on or in response tosending (e.g., transmitting) the at least one preamble and/or thetransport block. The response may correspond to the at least onepreamble, the transport block, and/or both.

The base station 120 may detect the at least one preamble and/or thetransport block. In response to the detecting, the response sent (e.g.,transmitted) from the base station may correspond to the at least onepreamble and/or the transport block. The base station 120 may detect theat least one preamble, but not detect the transport block. The responsesent (e.g., transmitted) from the base station 120 may correspond to theat least one preamble, for example, based on or in response to detectingthe at least one preamble, but not detecting the transport block.

The base station may detect the transport block, but not detect the atleast one preamble. The response sent (e.g., transmitted) from the basestation 120 may correspond to the transport block, for example, based onor in response to detecting the transport block, but not detecting theat least one preamble.

The response may comprise at least one of following: an RAR UL grant(e.g., radio resource assignment, and/or MCS), a wireless device ID forcontention resolution (e.g., a contention resolution message), an RNTI(e.g., C-RNTI or TC-RNTI), and/or other information. The response (e.g.,an RAR) may comprise a preamble identifier corresponding to the at leastone preamble, a positive (ACK) or negative acknowledgement (NACK) of areception of the transport block, and/or an indication of a successfuldecoding of the transport block. The wireless device 110 may send (e.g.,transmit) a second transport block, for example, based on the responsereceived from the base station 120.

Monitoring (e.g., listening) for the response may comprise attempting todetect DCI (e.g., DCI format 1_0) during a window 3010 (e.g.,ra-responseWindow). The one or more configuration parameters mayindicate (e.g., identify) the window 3010. The wireless device 110 maynotreceive the response during the window 3010 (e.g.,ra-responseWindow). Not receiving the response may comprise notreceiving the response corresponding to the at least one preamble and/orthe transport block. The wireless device 110 may determine (e.g.,consider) that the two-step random access procedure is incomplete (e.g.,preamble transmission counter variable is less than preamble maximumtransmission parameter plus one), for example, based on or in responseto not receiving a response from the base station 120.

The wireless device 110 may perform a second random access resourceselection, for example, based on or in response to not receiving theresponse during the window 3010. Failure to receive the response duringthe window 3010 may indicate the random access procedure is incomplete.The wireless device 110 may determine (e.g., select, choose) a secondPRACH resource of the one or more PRACH resources for the second randomaccess selection. The PRACH resource may comprise at least one secondpreamble and/or at least one second PRACH occasion (e.g., timeresource/occasion, frequency resource/occasion, code, etc.).

The wireless device 110 may determine (e.g., select) at least one secondUL radio resource of the one or more uplink radio resources, forexample, if the wireless device 110 performs the second random accessresource selection for the two-step random access procedure based on theone or more associations (e.g., mappings). The second PRACH resource maybe (e.g., one-to-one, one-to-many, many-to-one) associated (e.g.,mapped) with the at least one second UL radio resource (or at least oneuplink grant). The at least one second UL radio resource may comprise asecond time resource (e.g., occasion) and/or a second frequency resource(e.g., occasion) for a second uplink transmission of a second transportblock (e.g., Msg3, PUSCH). The second PRACH resource may comprise the atleast one second preamble of the second PRACH resource being associated(e.g., mapped) with the at least one second UL radio resource. Thesecond PRACH resource may comprise the at least one second PRACHoccasion of the second PRACH resource being associated (e.g., mapped)with the at least one second UL radio resource. The transport blockand/or the second transport block may be the same. The transport blockand/or the second transport block may be different.

At time T₄ 3012, the wireless device 110 may send (e.g., transmit) theat least one second preamble for the two-step random access procedurevia the at least one second PRACH occasion. The wireless device 110 maysend (e.g., transmit) the at least one second preamble for the two-steprandom access procedure, for example, based on the second random accessselection.

At time T₅ 3014, the wireless device 110 may send (e.g., transmit) thesecond transport block for the second uplink transmission for thetwo-step random access procedure via the at least one second UL radioresource. the wireless device 110 may send (e.g., transmit) the secondtransport block for the second uplink transmission for the two-steprandom access procedure, for example, based on or in response to thedetermining (e.g., selecting) the at least one second UL radio resource.

The wireless device 110 may send (e.g., transmit) the second transportblock with a second redundancy version (RV) in the RV sequence (e.g.,the second RV is equal to two in FIG. 30 ). The second RV may have asecond index in the redundancy version sequence. The second index may beequal to the first index plus one. In an RV sequence [0 2 3 1], thefirst RV may be 0 if the first index of the first RV is equal to one,and the second RV may be 2 if the second index of the second RV is equalto two (e.g., the first index plus one). In an RV sequence [0 2 3 1],the first RV may be 3 if the first index of the first RV is equal tothree, and the second RV may be 1 if the second index of the second RVis four (e.g., the first index plus one). The first index may be equalto the size (e.g., length) of the RV sequence (e.g., the first size isfour in FIG. 30 ). The second index may be one, for example, in responseto the first index being equal to the size (e.g., length) of the RVsequence. In an RV sequence [0 2 3 1] with the first index of the firstRV (e.g., 1) equal to four, which may be the same size (e.g., length) ofthe RV sequence [0 2 3 1], the second RV may be 0. The second index ofthe second RV (e.g., 0) may be one.

The wireless device 110 may determine the second index of the second RVusing a formula. The formula may be

mod(the first index+1, the size(e.g., length)of the RV sequence).

-   -   Given two positive numbers, a (the dividend) and n (the        divisor), mod (a, n) is the remainder of the Euclidean division        of a by n. For example, mod (5,3)=2, mod (6,3)=0, mod (5,1)=0,        mod (5,5)=0.

Based on the formula above, the second index of the second RV is equalto mod (1+1,4)=2, for example, if a redundancy version sequence is [0 23 1] and the first index of the first RV (e.g., 0) is one. The second RVmay be 2, for example, based on the second index being equal to two,which indicates 2 in the RV sequence. Based on the formula, the secondindex of the second RV may be equal to mod (4+1,4)=1, for example, if RVsequence is [0 2 3 1] and the first index of the first RV (e.g., 1) isfour. The second RV may be 0, for example, in response to the secondindex being equal to one indicating 0 in the RV sequence.

The wireless device 110 may set a redundancy version to a first value,for example, for the n^(th) transmission. The first value may becomputed from a second formula as a value of the (mod(n−1, the size(e.g., length) of the RV sequence)+1)^(th) entry in the RV sequence. Thewireless device 110 may determine n=1 for the uplink transmission of thetransport block at time T₃ 3008, for example, if the RV sequence is [0 23 1]. Based on the second formula (e.g., mod (1−1,4)+1=1), the wirelessdevice 110 may set the first redundancy version for the uplinktransmission to a 1st element (e.g., 0) in the RV sequence. The wirelessdevice may determine n=2 for the second uplink transmission of thesecond transport block at time T₅ 3014, for example, if the RV sequenceis [0 2 3 1]. Based on the second formula (e.g., mod (2−1,4)+1=2), thewireless device 110 may set the second RV for the second uplinktransmission to a 2^(nd) element (e.g., 2) in the RV sequence.

FIG. 31 shows that PRACH resource 1 3110 may be one-to-one associated(e.g., mapped) with uplink resource 1 3120. The wireless device maydetermine (e.g., select, choose) the uplink resource 1 3120 for anuplink transmission of a transport block (e.g., Msg3), for example,based on the one-to-one association (e.g., mapping) between PRACHresource 1 3110 and uplink resource 1 3120. The wireless may determine(e.g., select, choose) the uplink resource 1 3120, for example, if thewireless device selects the PRACH resource 1 3110 for a two-step randomaccess procedure. The base station may determine that the wirelessdevice selected the PRACH resource 1 3110 for a two-step random accessprocedure, for example, if the base station receives a transport blockon the uplink resource 1 3120. The base station may determine that thewireless device selected the PRACH resource 1 3110 for a two-step randomaccess procedure, for example, based on the one-to-one association(e.g., mapping) between PRACH resource 1 3110 and uplink resource 13120.

FIG. 31 also shows that PRACH resource 2 3112 may be associated with(e.g., mapped to) uplink resource 2 3122 and/or uplink resource 3 3124via a one-to-many association (e.g., mapping). The wireless device maydetermine (e.g., select, choose) the uplink resource 2 3122 and/or theuplink resource 3 3124 for an uplink transmission of a transport block(e.g., Msg3), for example, if the wireless device determines (e.g.,selects) the PRACH resource 2 3112 for a two-step random accessprocedure. The wireless device may determine (e.g., select, choose) theuplink resource 2 3122 for an uplink transmission of a transport block(e.g., Msg3), for example, based on the one-to-many association (e.g.,mapping) between PRACH resource 2 3112 and uplink resource 2 3122 and/oruplink resource 3 3124. The base station may determine that the wirelessdevice selected the PRACH resource 2 3112 for a two-step random accessprocedure, for example, if the base station receives a transport blockon the uplink resource 2 and/or the uplink resource 3. The base stationmay determine that the wireless device selected the PRACH resource 23112 for a two-step random access procedure, for example, based on theone-to-many association (e.g., mapping) between PRACH resource 2 3112and Uplink resource 2 3122 and/or Uplink resource 3 3124.

FIG. 31 shows that uplink resource 3 3124 may be a many-to-oneassociation (e.g., mapped) with PRACH resource 2 3112 and/or PRACHresource 3 3114. The wireless device may determine (e.g., select) theuplink resource 3 3124 for an uplink transmission of a transport block(e.g., Msg3), for example, if the wireless device selects the PRACHresource 2 3112 and/or the PRACH resource 3 for 3114 a two-step randomaccess procedure. The wireless device may determine (e.g., select) theuplink resource 3 3124 for an uplink transmission of a transport block(e.g., Msg3), for example, in response to the many-to-one association(e.g., mapping) between uplink resource 3 3124 and PRACH resource 2 3112and/or PRACH resource 3 3114. The base station may determine that thewireless device selected the PRACH resource 2 3112 and/or the PRACHresource 3 3114 for a two-step random access procedure, for example, ifthe base station receives a transport block on the uplink resource 33124. The base station may determine that the wireless device selectedthe PRACH resource 2 3112 and/or the PRACH resource 3 3114 for atwo-step random access procedure, for example, based on in response tothe many-to-one association (e.g., mapping) between uplink resource 33124 and PRACH resource 2 3112 and/or PRACH resource 3 3114.

FIG. 32 shows an example of a random access procedure. At time T₀ 3202,a wireless device 110 may receive one or more configuration parametersfrom a base station 120. The configuration parameters may compriseconfiguration parameters for a two-step random access (RA) procedure ofa cell (e.g., PCell, SCell). The one or more configuration parametersmay indicate (e.g., identify) one or more PRACH resources (e.g., PRACHresources in FIG. 32 ). The one or more PRACH resources may comprise oneor more RAPs. In an example, the one or more PRACH resources maycomprise one or more RACH occasions (e.g., time/frequency occasion). Theone or more configuration parameters may indicate one or more uplinkradio resources (e.g., in terms of time, frequency,code/sequence/signature). The configuration parameters may comprise oneor more uplink radio resources (e.g., Uplink resources in FIG. 32 ). Theone or more configuration parameters may indicate one or more uplinkgrants indicating one or more uplink radio resources (in terms of time,frequency, code/sequence/signature).

At time T₁ 3204, the wireless device 110 may start (e.g., initiate) atwo-step random access procedure (e.g., contention-free random accessprocedure, contention-based random access procedure) for the cell. Thewireless device 110 may perform a first random access resourceselection, for example, based on or in response to initiating thetwo-step random access procedure. The wireless device 110 may determine(e.g., select) a random access channel (PRACH) resource of the one ormore PRACH resources for the first random access selection. The PRACHresource may comprise at least one preamble. The PRACH resource maycomprise at least one PRACH occasion (e.g., time resource/occasion,frequency resource/occasion, code, etc.).

At time T₂ 3206, the wireless device 110 may send (e.g., transmit) theat least one preamble for the two-step random access procedure via theat least one PRACH occasion. The at least one preamble may be sent(e.g., transmitted) via the at least one PRACH occasion, for example,based on the first random access selection. At time T₃ 3208, thewireless device 110 may send (e.g., transmit) the transport block forthe uplink transmission for the two-step random access procedure via theat least one UL radio resource. The transport block may be sent (e.g.,transmitted), for example, based on or in response to the determining(e.g., selecting) the at least one UL radio resource. The wirelessdevice 110 may send (e.g., transmit) the transport block with a firstredundancy version (RV) in the RV sequence (e.g., the first RV is 0 inFIG. 30 ). The first RV may have a first index in the redundancy versionsequence. In a redundancy version sequence [0 2 3 1], the first indexmay be equal to 1 if the first RV is 0; the first index may be equal to2 if the first RV is 2; the first index may be equal to 3 if the firstRV is 3; and the first index may be equal to 4 if the first RV is 1. Inanother example with a redundancy version sequence [0 1 2 3], the firstindex may be equal to 1 if the first RV is 0; the first index may beequal to 2 if the first RV is 1; the first index may be equal to 3 ifthe first RV is 2; and the first index may be equal to 4 if the first RVis 3.

Sending (e.g., transmitting) the at least one preamble may overlap intime and/or in frequency (partially or entirely) with the uplinktransmission of the transport block. The at least one PRACH occasion maybe multiplexed with the at least one UL radio resource in the timeand/or frequency domain (e.g., TDM-ed, FDM-ed). The wireless device 110may send (e.g., transmit) the at least one preamble and/or the at leastone UL radio resource simultaneously (e.g., T₂ 3206 and T₃ 3208 may bethe same), for example, if the at least one PRACH occasion ismultiplexed with the at least one UL radio resource in a frequencydomain. The wireless device 110 may send (e.g., transmit) the at leastone preamble and/or the transport block at different times with a timegap (e.g., T₂ 3006 and T₃ 3008 may be different), for example, if the atleast one PRACH occasion is multiplexed with the at least one UL radioresource in a time domain. The wireless device 110 may monitor (e.g.,listen) for a response (e.g., random access response, two-step Msg2,MsgB) from the base station 120, for example, based on or in response tosending (e.g., transmitting) the at least one preamble and/or thetransport block. The response may correspond to the at least onepreamble, the transport block, and/or both.

Monitoring (e.g., listening) for the response may comprise attempting todetect DCI (e.g., DCI format 1_0) during a window 3210 (e.g.,ra-responseWindow). The one or more configuration parameters mayindicate the window 3210. The wireless device 110 may not receive theresponse during the window 3210 (e.g., ra-responseWindow). Not receivingthe response may comprise not receiving the response corresponding tothe at least one preamble and/or the transport block. The wirelessdevice 110 may determine (e.g., consider) that the two-step randomaccess procedure is incomplete (e.g., preamble transmission countervariable is less than preamble maximum transmission parameter plus one),for example, based on or in response to not receiving a response fromthe base station 120.

The wireless device 110 may perform a second random access resourceselection, for example, based on or in response to not receiving theresponse during the window 3210. Failure to receive the response duringthe window 3210 may indicate the random access procedure is incomplete.The wireless device 110 may determine (e.g., select, choose) a secondPRACH resource of the one or more PRACH resources for the second randomaccess selection. The PRACH resource may comprise at least one secondpreamble and/or at least one second PRACH occasion (e.g., timeresource/occasion, frequency resource/occasion, code, etc.).

The wireless device 110 may determine (e.g., select) at least one secondUL radio resource of the one or more uplink radio resources, forexample, if the wireless device 110 performs the second random accessresource selection for the two-step random access procedure based on theone or more associations (e.g., mappings). The second PRACH resource maybe (e.g., one-to-one, one-to-many, many-to-one) associated (e.g.,mapped) with the at least one second UL radio resource (or at least oneuplink grant). The at least one second UL radio resource may comprise asecond time resource (e.g., occasion) and/or a second frequency resource(e.g., occasion) for a second uplink transmission of a second transportblock (e.g., Msg3, PUSCH). The second PRACH resource may comprise the atleast one second preamble of the second PRACH resource being associated(e.g., mapped) with the at least one second UL radio resource. Thesecond PRACH resource may comprise the at least one second PRACHoccasion of the second PRACH resource being associated (e.g., mapped)with the at least one second UL radio resource. The transport blockand/or the second transport block may be the same. The transport blockand/or the second transport block may be different.

At time T₄ 3212, the wireless device 110 may send (e.g., transmit) theat least one second preamble for the two-step random access procedurevia the at least one second PRACH occasion. The wireless device 110 maysend (e.g., transmit) the at least one second preamble for the two-steprandom access procedure, for example, based on the second random accessselection. The two-step random access procedure may be acontention-based random access procedure. The wireless device 110 maysend (e.g., transmit) the second transport block with a secondredundancy version (RV) in the RV sequence, for example, based on or inresponse to the two-step random access procedure being thecontention-based random access procedure. At time T₅ 3214, the second RVmay be equal to the first RV (e.g., 0). The wireless device 110 may send(e.g., transmit) the transport block with the first RV (e.g., 0) at timeT₃ 3208. At time T₅ 3214, the wireless device 110 may send (e.g.,transmit) the second transport block with the first RV (e.g., 0), forexample, for example based on or in response to the second RV beingequal to the first RV.

The two-step random access procedure may be a contention-free randomaccess procedure. The wireless device 110 may send (e.g., transmit) thesecond transport block with a second RV in the RV sequence, for example,based on or in response to the two-step random access procedure beingthe contention-free random access procedure. The wireless device maydetermine the second RV based on the formula (e.g., mod (the firstindex+1, the size (e.g., length) of the RV sequence)). At time T₃ 3208,the wireless device 110 may send (e.g., transmit) the transport blockwith the first RV (e.g., 0). At time T₅ 3214, the wireless device 110may send (e.g., transmit) the second transport block with the second RV(e.g., 2), for example, based on the formula above.

FIG. 33 shows an example of a random access procedure. At time T₀ 3302,a wireless device 110 may receive one or more configuration parametersfrom a base station 120. The configuration parameters may compriseconfiguration parameters for a two-step random access (RA) procedure ofa cell (e.g., PCell, SCell). The one or more configuration parametersmay indicate (e.g., identify) one or more PRACH resources (e.g., PRACHresources in FIG. 33 ). The one or more PRACH resources may comprise oneor more RAPs. The one or more PRACH resources may comprise one or moreRACH occasions (e.g., time/frequency occasion). The one or moreconfiguration parameters may indicate one or more uplink radio resources(in terms of time, frequency, code/sequence/signature). Theconfiguration parameters may comprise one or more uplink radio resources(e.g., Uplink resources in FIG. 33 ). The one or more configurationparameters may indicate one or more uplink grants indicating (e.g.,identifying) one or more uplink radio resources (in terms of time,frequency, code/sequence/signature).

The base station 120 may broadcast one or more uplink radio resources(in terms of time, frequency, code/sequence/signature). A plurality ofwireless devices (in the cell) may share the one or more uplink radioresources, for example, based on or in response to broadcasting the oneor more uplink resources. The one or more configuration parameters mayindicate (e.g., identify) one or more associations (e.g., mappings)between the one or more uplink radio resources and the one or more PRACHresources. The one or more configuration parameters may indicate (e.g.,identify) one or more associations (e.g., mappings) between the one ormore uplink radio resources and the one or more RAPs of the one or morePRACH resources. The one or more configuration parameters may indicate(e.g., identify) one or more associations (e.g., mappings) between theone or more uplink radio resources and the one or more RACH occasions ofthe one or more PRACH resources. The one or more configurationparameters may indicate (e.g., identify) a redundancy version (RV)sequence (e.g., [0 0 0 0], [0 2 3 1], [0 3 0]) for the one or moreuplink radio resources. As shown in FIG. 33 , the redundancy versionsequence may be [0 2 3 1].

At time T₁ 3304, the wireless device 110 may start (e.g., initiate) atwo-step random access procedure (e.g., contention-free random accessprocedure, contention-based random access procedure) for the cell. Thewireless device 110 may perform a first random access resourceselection, for example, based on or in response to starting (e.g.,initiating) the two-step random access procedure. The wireless device110 may determine (e.g., select) a random access channel (PRACH)resource of the one or more PRACH resources for the first random accessselection. The PRACH resource may comprise at least one preamble. ThePRACH resource may comprise at least one PRACH occasion (e.g., timeresource/occasion, frequency resource/occasion, code, etc.).

The wireless device may determine (e.g., select) at least one UL radioresource of the one or more uplink radio resources, for example, if thewireless device performs the first random access resource selection forthe two-step random access procedure. The first random access resourceselection may be based on the one or more associations (e.g., mappings).The PRACH resource may be (e.g., one-to-one, one-to-many, many-to-one)associated (e.g., mapped) with the at least one UL radio resource (or atleast one uplink grant). The at least one UL radio resource may comprisea time resource (e.g., occasion) and/or a frequency resource (e.g.,occasion) for an uplink transmission of a transport block (e.g., Msg3,PUSCH). The PRACH resource being associated (e.g., mapped) with the atleast one UL radio resource may comprise the at least one preamble ofthe PRACH resource being associated (e.g., mapped) with the at least oneUL radio resource. The PRACH resource being associated (e.g., mapped)with the at least one UL radio resource may comprise the at least onePRACH occasion of the PRACH resource being associated (e.g., mapped)with the at least one UL radio resource.

At time T₂ 3306, the wireless device 110 may send (e.g., transmit) theat least one preamble for the two-step random access procedure via theat least one PRACH occasion. The at least one preamble may be sent(e.g., transmitted) via the at least one PRACH occasion, for example,based on the first random access selection. At time T₃ 3008, thewireless device 110 may send (e.g., transmit) the transport block forthe uplink transmission for the two-step random access procedure via theat least one UL radio resource. The wireless device 110 may monitor(e.g., listen) for a response (e.g., random access response, two-stepMsg2, MsgB) from the base station 120, for example, in response tosending (e.g., transmitting) the at least one preamble and/or thetransport block during window 3310. The response may correspond to theat least one preamble, the transport block, and/or both.

The base station 120 may detect the at least one preamble, but notdetect the transport block. The response sent (e.g., transmitted) fromthe base station 120 may correspond to the at least one preamble, forexample, based on or in response to detecting the at least one preamblebut not detecting the transport block. The response may be a randomaccess response (RAR) corresponding to the at least one preamble. Thewireless device 110 may fall back from the two-step random accessprocedure to a four-step random access procedure, for example, based onor in response to receiving the random access response corresponding tothe at least one preamble. The two-step random access procedure may be acontention-free random access procedure.

The random access response may comprise an UL grant (e.g., RAR ULgrant). The UL grant may schedule a second uplink transmission (e.g.,PUSCH) for a second transport block (e.g., Msg3, PUSCH) for thefour-step random access procedure. The wireless device 110 may send(e.g., transmit) the second transport block for the second uplinktransmission, for example, via at least one second UL radio resource(e.g., a second time resource/occasion and/or a second frequencyresource/occasion). The UL grant may indicate (e.g., identify) the atleast one second UL radio resource. At time T₄ 3312, the wireless device110 may send (e.g., transmit) the second transport block with a secondRV in the RV sequence (e.g., the second RV is equal to two). The secondRV may have a second index in the RV sequence. The second index may beequal to the first index plus one. In an RV sequence [0 2 3 1], thefirst RV (e.g., 0) may be equal to one if the first index is equal toone, and the second RV (e.g., 2) may be two if the second index is equalto two (e.g., the first index plus one). The first index may be equal tothe size (e.g., length) of the RV sequence (e.g., as shown in FIG. 33 ,the first size is four). The second index may be one, for example, basedon or in response to the first index being equal to the size (e.g.,length) of the RV sequence. The second RV may be 0, for example, if anRV sequence is [0 2 3 1] and/or the first index of the first RV(e.g., 1) is equal to four, which is same size (e.g., length) of the RVsequence [0 2 3 1]. The second index of the second RV (e.g., 0) may beone.

The wireless device 110 may determine the second index of the second RVbased on a formula. The formula may be mod (the first index+1, the size(e.g., length) of the RV sequence).

The second index of the second RV may be equal to mod (1+1,4)=2, forexample, if an RV sequence is [0 2 3 1] and/or the first index of thefirst RV (e.g., 0) is one. The second RV may be 2, for example, based onor in response to the second index being equal to two indicating 2 inthe RV sequence. The second index of the second RV may be equal to mod(4+1,4)=1, for example, if an RV sequence is [0 2 3 1] and/or the firstindex of the first RV (e.g., 1) is four. The second RV may be 0, forexample, based on or in response to the second index being equal to oneindicating 0 in the RV sequence

Sending (e.g., transmitting) with different RVs (e.g., with RV=0 in thefirst transport block and RV=2 in the second transport block) mayimprove the decoding gain. The base station 120 may combine (e.g.,reassemble) the transport block and/or the second transport block toimprove the decoding performance. As additional parity and redundantinformation bits may be sent (e.g., transmitted) in each transmission,the base station 120 may combine (e.g., reassemble) the second uplinktransmission with the first uplink transmission resulting in code rategain. At each transmission the base station 120 may gain extrainformation. The base station 120 may not provide the wireless device110 with the RV sequence. The wireless device 110 may set the first RVfor the uplink transmission to zero, for example, based on or inresponse to not being provided with the RV sequence. The wireless device110 may set the second redundancy version for the second uplinktransmission to zero, for example, based on or in response to not beingprovided with the RV sequence.

A wireless device may send, as part of a random access procedure, afirst transmission comprising a preamble and a transport blockcomprising a first redundancy version. The wireless device may resendthe transport block with the first redundancy version based on adetermination that a random access response associated with thetransport block has not been received. The wireless device may receive,from a base station, one or more configuration parameters, wherein theone or more configuration parameters comprise a redundancy versionsequence. The one or more configuration parameters may further comprise:one or more physical random-access channel (PRACH) resources, one ormore uplink resources, and one or more mappings between the one or morePRACH resources and the one or more uplink resources. The wirelessdevice may resend the transport block with a second redundancy versionfrom the redundancy version sequence. The wireless device may send arandom access preamble with the transport block comprising the firstredundancy version as part of a two-step random access procedure. Thewireless device may resend the random access preamble based on adetermination that a second random access response corresponding to arandom access preamble has not been received. The first redundancyversion may be equal to zero. The wireless device may receive a secondrandom access response corresponding to a random access preamble. Thesecond random access responses may comprise an uplink grant indicatingan uplink resource. The wireless device may resend the transport blockvia the uplink resource indicated by the uplink grant in the secondrandom access response. The wireless device may send a secondtransmission comprising a second preamble as part of a secondrandom-access procedure. The wireless device may send a thirdtransmission as part of the second random-access procedure. The thirdtransmission may comprise: the transport block; and a second redundancyversion. The random access procedure may comprise either acontention-free random access procedure and/or a contention-based randomaccess procedure.

A wireless device may receive one or more messages comprising one ormore configuration parameters for a cell. The one or more configurationparameters may indicate a redundancy version sequence. The one or moreconfiguration parameters may further comprise: one or more physicalrandom access channel (PRACH) resources; one or more uplink resources;and one or more mappings between the one or more PRACH resources and theone or more uplink resources. The wireless device may start a randomaccess procedure for the cell. The wireless device may send a transportblock comprising a first redundancy version of the redundancy versionsequence. The wireless device may resend the transport block with asecond redundancy version of the redundancy version sequence based on adetermination that a random access response corresponding to thetransport block has not been received. The random-access procedure maycomprise a two-step random access procedure. The wireless device maysend a random-access preamble with the transport block comprising thefirst redundancy version. The wireless device may resend the randomaccess preamble based on a determination that a second random accessresponse corresponding to the random access preamble has not beenreceived. The wireless device may determine the random access procedurefor the cell based on a random access resource selection procedure. Thefirst redundancy version and the second redundancy version may be equal.

A wireless device may receive one or more messages comprising one ormore configuration parameters. The one or more configuration parametersmay indicate a redundancy version sequence. The wireless device may senda transport block comprising a first redundancy version of theredundancy version sequence. The wireless device may resend thetransport block with the first redundancy version based on adetermination that a random access response corresponding to thetransport block has not been received. The wireless device may send arandom-access preamble with the transport block comprising the firstredundancy version as part of a two-step random-access procedure. Thewireless device may receive a second random access responsecorresponding to a random access preamble. The second random accessresponse may comprise a second redundancy version. The wireless devicemay resend the transport block with the second redundancy version.

FIG. 34 shows example elements of a computing device that may be used toimplement any of the various devices described herein, including, e.g.,the base station 120A and/or 120B, the wireless device 110 (e.g., 110Aand/or 110B), or any other base station, wireless device, or computingdevice described herein. The computing device 3400 may include one ormore processors 3401, which may execute instructions stored in therandom access memory (RAM) 3403, the removable media 3404 (such as aUniversal Serial Bus (USB) drive, compact disk (CD) or digital versatiledisk (DVD), or floppy disk drive), or any other desired storage medium.Instructions may also be stored in an attached (or internal) hard drive3405. The computing device 3400 may also include a security processor(not shown), which may execute instructions of one or more computerprograms to monitor the processes executing on the processor 3401 andany process that requests access to any hardware and/or softwarecomponents of the computing device 3400 (e.g., ROM 3402, RAM 3403, theremovable media 3404, the hard drive 3405, the device controller 3407, anetwork interface 3409, a GPS 3411, a Bluetooth interface 3412, a WiFiinterface 3413, etc.). The computing device 3400 may include one or moreoutput devices, such as the display 3406 (e.g., a screen, a displaydevice, a monitor, a television, etc.), and may include one or moreoutput device controllers 3407, such as a video processor. There mayalso be one or more user input devices 3408, such as a remote control,keyboard, mouse, touch screen, microphone, etc. The computing device3400 may also include one or more network interfaces, such as a networkinterface 3409, which may be a wired interface, a wireless interface, ora combination of the two. The network interface 3409 may provide aninterface for the computing device 3400 to communicate with a network3410 (e.g., a RAN, or any other network). The network interface 3409 mayinclude a modem (e.g., a cable modem), and the external network 3410 mayinclude communication links, an external network, an in-home network, aprovider's wireless, coaxial, fiber, or hybrid fiber/coaxialdistribution system (e.g., a DOCSIS network), or any other desirednetwork. Additionally, the computing device 3400 may include alocation-detecting device, such as a global positioning system (GPS)microprocessor 3411, which may be configured to receive and processglobal positioning signals and determine, with possible assistance froman external server and antenna, a geographic position of the computingdevice 3400.

The example in FIG. 34 may be a hardware configuration, although thecomponents shown may be implemented as software as well. Modificationsmay be made to add, remove, combine, divide, etc. components of thecomputing device 3400 as desired. Additionally, the components may beimplemented using basic computing devices and components, and the samecomponents (e.g., processor 3401, ROM storage 3402, display 3406, etc.)may be used to implement any of the other computing devices andcomponents described herein. For example, the various componentsdescribed herein may be implemented using computing devices havingcomponents such as a processor executing computer-executableinstructions stored on a computer-readable medium, as shown in FIG. 34 .Some or all of the entities described herein may be software based, andmay co-exist in a common physical platform (e.g., a requesting entitymay be a separate software process and program from a dependent entity,both of which may be executed as software on a common computing device).

The disclosed mechanisms herein may be performed if certain criteria aremet, for example, in a wireless device, a base station, a radioenvironment, a network, a combination of the above, and/or the like.Example criteria may be based on, for example, wireless device and/ornetwork node configurations, traffic load, initial system set up, packetsizes, traffic characteristics, a combination of the above, and/or thelike. If the one or more criteria are met, various examples may be used.It may be possible to implement examples that selectively implementdisclosed protocols.

A base station may communicate with a mix of wireless devices. Wirelessdevices and/or base stations may support multiple technologies, and/ormultiple releases of the same technology. Wireless devices may have somespecific capability(ies) depending on wireless device category and/orcapability(ies). A base station may comprise multiple sectors. A basestation communicating with a plurality of wireless devices may refer tobase station communicating with a subset of the total wireless devicesin a coverage area. Wireless devices referred to herein may correspondto a plurality of wireless devices of a particular LTE or 5G releasewith a given capability and in a given sector of a base station. Aplurality of wireless devices may refer to a selected plurality ofwireless devices, and/or a subset of total wireless devices in acoverage area. Such devices may operate, function, and/or perform basedon or according to drawings and/or descriptions herein, and/or the like.There may be a plurality of base stations or a plurality of wirelessdevices in a coverage area that may not comply with the disclosedmethods, for example, because those wireless devices and/or basestations perform based on older releases of LTE or 5G technology.

One or more features described herein may be implemented in acomputer-usable data and/or computer-executable instructions, such as inone or more program modules, executed by one or more computers or otherdevices. Generally, program modules include routines, programs, objects,components, data structures, etc. that perform particular tasks orimplement particular abstract data types when executed by a processor ina computer or other data processing device. The computer executableinstructions may be stored on one or more computer readable media suchas a hard disk, optical disk, removable storage media, solid statememory, RAM, etc. The functionality of the program modules may becombined or distributed as desired. The functionality may be implementedin whole or in part in firmware or hardware equivalents such asintegrated circuits, field programmable gate arrays (FPGA), and thelike. Particular data structures may be used to more effectivelyimplement one or more features described herein, and such datastructures are contemplated within the scope of computer executableinstructions and computer-usable data described herein.

Many of the elements in examples may be implemented as modules. A modulemay be an isolatable element that performs a defined function and has adefined interface to other elements. The modules may be implemented inhardware, software in combination with hardware, firmware, wetware(i.e., hardware with a biological element) or a combination thereof, allof which may be behaviorally equivalent. For example, modules may beimplemented as a software routine written in a computer languageconfigured to be executed by a hardware machine (such as C, C++,Fortran, Java, Basic, Matlab or the like) or a modeling/simulationprogram such as Simulink, Stateflow, GNU Octave, or LabVIEWMathScript.Additionally, or alternatively, it may be possible to implement modulesusing physical hardware that incorporates discrete or programmableanalog, digital and/or quantum hardware. Examples of programmablehardware may comprise: computers, microcontrollers, microprocessors,application-specific integrated circuits (ASICs); field programmablegate arrays (FPGAs); and complex programmable logic devices (CPLDs).Computers, microcontrollers, and microprocessors may be programmed usinglanguages such as assembly, C, C++ or the like. FPGAs, ASICs, and CPLDsmay be programmed using hardware description languages (HDL), such asVHSIC hardware description language (VHDL) or Verilog, which mayconfigure connections between internal hardware modules with lesserfunctionality on a programmable device. The above-mentioned technologiesmay be used in combination to achieve the result of a functional module.

A non-transitory tangible computer readable media may compriseinstructions executable by one or more processors configured to causeoperations of multi-carrier communications described herein. An articleof manufacture may comprise a non-transitory tangible computer readablemachine-accessible medium having instructions encoded thereon forenabling programmable hardware to cause a device (e.g., a wirelessdevice, wireless communicator, a wireless device, a base station, andthe like) to allow operation of multi-carrier communications describedherein. The device, or one or more devices such as in a system, mayinclude one or more processors, memory, interfaces, and/or the like.Other examples may comprise communication networks comprising devicessuch as base stations, wireless devices or user equipment (wirelessdevice), servers, switches, antennas, and/or the like. A network maycomprise any wireless technology, including but not limited to,cellular, wireless, WiFi, 4G, 5G, any generation of 3GPP or othercellular standard or recommendation, wireless local area networks,wireless personal area networks, wireless ad hoc networks, wirelessmetropolitan area networks, wireless wide area networks, global areanetworks, space networks, and any other network using wirelesscommunications. Any device (e.g., a wireless device, a base station, orany other device) or combination of devices may be used to perform anycombination of one or more of steps described herein, including, forexample, any complementary step or steps of one or more of the abovesteps.

Although examples are described above, features and/or steps of thoseexamples may be combined, divided, omitted, rearranged, revised, and/oraugmented in any desired manner. Various alterations, modifications, andimprovements will readily occur to those skilled in the art. Suchalterations, modifications, and improvements are intended to be part ofthis description, though not expressly stated herein, and are intendedto be within the spirit and scope of the descriptions herein.Accordingly, the foregoing description is by way of example only, and isnot limiting.

1. A method comprising: sending, by a wireless device, a physical randomaccess channel (PRACH) transmission comprising a random access preambleassociated with a first message of a two-step random access procedure;and after transmission of the first message and based on the randomaccess procedure being a two-step random access procedure, sending aphysical uplink shared channel (PUSCH) transmission comprising atransport block using a redundancy version set to zero.
 2. The method ofclaim 1, further comprising: receiving, by the wireless device from abase station, one or more configuration parameters indicating aredundancy version sequence.
 3. The method of claim 2, wherein the oneor more configuration parameters further indicate: one or more physicalrandom access channel (PRACH) resources; one or more uplink resources;and one or more mappings between the one or more PRACH resources and theone or more uplink resources.
 4. The method of claim 1, wherein thetwo-step random access procedure comprises a contention-based randomaccess procedure.
 5. The method of claim 1, wherein the first messagecomprises Msg A.
 6. The method of claim 1, further comprising:resending, based on a determination that a random access responseassociated with the transport block has not been received, the transportblock with the redundancy version set to zero.
 7. The method of claim 6,wherein the determination that the random access response associatedwith the transport block has not been received is based on at least oneof: not having received the random access response during a responsewindow; or an expiration of a timer.
 8. The method of claim 1, whereinthe PUSCH transmission comprises a retransmission of an earlier PUSCHtransmission associated with the first message.
 9. A wireless devicecomprising: one or more processors; and memory storing instructionsthat, when executed by the one or more processors, cause the wirelessdevice to: send a physical random access channel (PRACH) transmissioncomprising a random access preamble associated with a first message of atwo-step random access procedure; and after transmission of the firstmessage and based on the random access procedure being a two-step randomaccess procedure, send a physical uplink shared channel (PUSCH)transmission comprising a transport block using a redundancy version setto zero.
 10. The wireless device of claim 9, wherein the instructions,when executed by the one or more processors, cause the wireless deviceto: receive, from a base station, one or more configuration parametersindicating a redundancy version sequence.
 11. The wireless device ofclaim 10, wherein the one or more configuration parameters furtherindicate: one or more physical random access channel (PRACH) resources;one or more uplink resources; and one or more mappings between the oneor more PRACH resources and the one or more uplink resources.
 12. Thewireless device of claim 9, wherein the two-step random access procedurecomprises a contention-based random access procedure.
 13. The wirelessdevice of claim 9, wherein the first message comprises Msg A.
 14. Thewireless device of claim 9, wherein the instructions, when executed bythe one or more processors, cause the wireless device to: resend, basedon a determination that a random access response associated with thetransport block has not been received, the transport block with theredundancy version set to zero.
 15. The wireless device of claim 14,wherein the instructions, when executed by the one or more processors,cause the wireless device to: determine that the random access responseassociated with the transport block has not been received based on atleast one of: not having received the random access response during aresponse window; or an expiration of a timer.
 16. The wireless device ofclaim 9, wherein the PUSCH transmission comprises a retransmission of anearlier PUSCH transmission associated with the first message.
 17. Anon-transitory computer-readable medium comprising instructions that,when executed, configure a wireless device to: send a physical randomaccess channel (PRACH) transmission comprising a random access preambleassociated with a first message of a two-step random access procedure;and after transmission of the first message and based on the randomaccess procedure being a two-step random access procedure, send aphysical uplink shared channel (PUSCH) transmission comprising atransport block using a redundancy version set to zero.
 18. Thenon-transitory computer-readable medium of claim 17, wherein theinstructions, when executed, configure the wireless device to: receive,from a base station, one or more configuration parameters indicating aredundancy version sequence.
 19. The non-transitory computer-readablemedium of claim 18, wherein the one or more configuration parametersfurther indicate: one or more physical random access channel (PRACH)resources; one or more uplink resources; and one or more mappingsbetween the one or more PRACH resources and the one or more uplinkresources.
 20. The non-transitory computer-readable medium of claim 17,wherein the two-step random access procedure comprises acontention-based random access procedure.
 21. The non-transitorycomputer-readable medium of claim 17, wherein the first messagecomprises Msg A.
 22. The non-transitory computer-readable medium ofclaim 17, wherein the instructions, when executed, configure thewireless device to: resend, based on a determination that a randomaccess response associated with the transport block has not beenreceived, the transport block with the redundancy version set to zero.23. The non-transitory computer-readable medium of claim 22, wherein theinstructions, when executed, configure the wireless device to: determinethat the random access response associated with the transport block hasnot been received based on at least one of: not having received therandom access response during a response window; or an expiration of atimer.
 24. The non-transitory computer-readable medium of claim 17,wherein the PUSCH transmission comprises a retransmission of an earlierPUSCH transmission associated with the first message.
 25. A methodcomprising: receiving, by a base station, a physical random accesschannel (PRACH) transmission comprising a random access preambleassociated with a first message of a two-step random access procedure;and after receiving the first message, receiving a physical uplinkshared channel (PUSCH) transmission comprising a transport block using aredundancy version set to zero.
 26. The method of claim 25, furthercomprising: sending, by the base station, one or more configurationparameters indicating a redundancy version sequence.
 27. The method ofclaim 26, wherein the one or more configuration parameters furtherindicate: one or more physical random access channel (PRACH) resources;one or more uplink resources; and one or more mappings between the oneor more PRACH resources and the one or more uplink resources.
 28. Themethod of claim 25, wherein the first message comprises Msg A.
 29. Themethod of claim 25, further comprising: sending, based on at least oneof the PRACH transmission or the PUSCH transmission, a random accessresponse.
 30. The method of claim 29, further comprising: receiving asecond PUSCH transmission comprising the transport block using theredundancy version set to zero.